[RFC] DisplayPort MST support

[RFC] DisplayPort MST support

[Dave Airlie]

Hey,

So this set is pretty close to what I think we should be merging initially,

Since the last set, it makes fbcon and suspend/resume work a lot better,

I've also fixed a couple of bugs in -intel that make things work a lot
better.

I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
to add 3 monitor support.

It still generates a fair few i915 state checker backtraces, and some
of them are fairly hard to work out, it might be we should just tone
down the state checker for encoders/connectors with no actual hw backing
them.

Dave.

[PATCH 01/11] drm/dp_helper: add defines for DP 1.2 and MST support.

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This just adds the defines from the DP 1.2 spec, which we
will use later.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 include/drm/drm_dp_helper.h | 78 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index cfcacec..879836d 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -37,6 +37,7 @@
  * eDP: Embedded DisplayPort version 1
  * DPI: DisplayPort Interoperability Guideline v1.1a
  * 1.2: DisplayPort 1.2
+ * MST: Multistream Transport - part of DP 1.2a
  *
  * 1.2 formally includes both eDP and DPI definitions.
  */
@@ -103,9 +104,14 @@
 #define DP_TRAINING_AUX_RD_INTERVAL         0x00e   /* XXX 1.2? */
 
 /* Multiple stream transport */
+#define DP_FAUX_CAP			    0x020   /* 1.2 */
+# define DP_FAUX_CAP_1			    (1 << 0)
+
 #define DP_MSTM_CAP			    0x021   /* 1.2 */
 # define DP_MST_CAP			    (1 << 0)
 
+#define DP_GUID				    0x030   /* 1.2 */
+
 #define DP_PSR_SUPPORT                      0x070   /* XXX 1.2? */
 # define DP_PSR_IS_SUPPORTED                1
 #define DP_PSR_CAPS                         0x071   /* XXX 1.2? */
@@ -221,6 +227,16 @@
 # define DP_PSR_CRC_VERIFICATION	    (1 << 2)
 # define DP_PSR_FRAME_CAPTURE		    (1 << 3)
 
+#define DP_ADAPTER_CTRL			    0x1a0
+# define DP_ADAPTER_CTRL_FORCE_LOAD_SENSE   (1 << 0)
+
+#define DP_BRANCH_DEVICE_CTRL		    0x1a1
+# define DP_BRANCH_DEVICE_IRQ_HPD	    (1 << 0)
+
+#define DP_PAYLOAD_ALLOCATE_SET		    0x1c0
+#define DP_PAYLOAD_ALLOCATE_START_TIME_SLOT 0x1c1
+#define DP_PAYLOAD_ALLOCATE_TIME_SLOT_COUNT 0x1c2
+
 #define DP_SINK_COUNT			    0x200
 /* prior to 1.2 bit 7 was reserved mbz */
 # define DP_GET_SINK_COUNT(x)		    ((((x) & 0x80) >> 1) | ((x) & 0x3f))
@@ -230,6 +246,9 @@
 # define DP_REMOTE_CONTROL_COMMAND_PENDING  (1 << 0)
 # define DP_AUTOMATED_TEST_REQUEST	    (1 << 1)
 # define DP_CP_IRQ			    (1 << 2)
+# define DP_MCCS_IRQ			    (1 << 3)
+# define DP_DOWN_REP_MSG_RDY		    (1 << 4) /* DP MST */
+# define DP_UP_REQ_MSG_RDY		    (1 << 5) /* DP MST */
 # define DP_SINK_SPECIFIC_IRQ		    (1 << 6)
 
 #define DP_LANE0_1_STATUS		    0x202
@@ -294,6 +313,13 @@
 #define DP_TEST_SINK			    0x270
 #define DP_TEST_SINK_START	    (1 << 0)
 
+#define DP_PAYLOAD_TABLE_UPDATE_STATUS      0x2c0   /* 1.2 MST */
+# define DP_PAYLOAD_TABLE_UPDATED           (1 << 0)
+# define DP_PAYLOAD_ACT_HANDLED             (1 << 1)
+
+#define DP_VC_PAYLOAD_ID_SLOT_1             0x2c1   /* 1.2 MST */
+/* up to ID_SLOT_63 at 0x2ff */
+
 #define DP_SOURCE_OUI			    0x300
 #define DP_SINK_OUI			    0x400
 #define DP_BRANCH_OUI			    0x500
@@ -303,6 +329,21 @@
 # define DP_SET_POWER_D3                    0x2
 # define DP_SET_POWER_MASK                  0x3
 
+#define DP_SIDEBAND_MSG_DOWN_REQ_BASE	    0x1000   /* 1.2 MST */
+#define DP_SIDEBAND_MSG_UP_REP_BASE	    0x1200   /* 1.2 MST */
+#define DP_SIDEBAND_MSG_DOWN_REP_BASE	    0x1400   /* 1.2 MST */
+#define DP_SIDEBAND_MSG_UP_REQ_BASE	    0x1600   /* 1.2 MST */
+
+#define DP_SINK_COUNT_ESI		    0x2002   /* 1.2 */
+/* 0-5 sink count */
+# define DP_SINK_COUNT_CP_READY             (1 << 6)
+
+#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0   0x2003   /* 1.2 */
+
+#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1   0x2004   /* 1.2 */
+
+#define DP_LINK_SERVICE_IRQ_VECTOR_ESI0     0x2005   /* 1.2 */
+
 #define DP_PSR_ERROR_STATUS                 0x2006  /* XXX 1.2? */
 # define DP_PSR_LINK_CRC_ERROR              (1 << 0)
 # define DP_PSR_RFB_STORAGE_ERROR           (1 << 1)
@@ -319,6 +360,43 @@
 # define DP_PSR_SINK_INTERNAL_ERROR         7
 # define DP_PSR_SINK_STATE_MASK             0x07
 
+/* DP 1.2 Sideband message defines */
+/* peer device type - DP 1.2a Table 2-92 */
+#define DP_PEER_DEVICE_NONE		0x0
+#define DP_PEER_DEVICE_SOURCE_OR_SST	0x1
+#define DP_PEER_DEVICE_MST_BRANCHING	0x2
+#define DP_PEER_DEVICE_SST_SINK		0x3
+#define DP_PEER_DEVICE_DP_LEGACY_CONV	0x4
+
+/* DP 1.2 MST sideband request names DP 1.2a Table 2-80 */
+#define DP_LINK_ADDRESS			0x01
+#define DP_CONNECTION_STATUS_NOTIFY	0x02
+#define DP_ENUM_PATH_RESOURCES		0x10
+#define DP_ALLOCATE_PAYLOAD		0x11
+#define DP_QUERY_PAYLOAD		0x12
+#define DP_RESOURCE_STATUS_NOTIFY	0x13
+#define DP_CLEAR_PAYLOAD_ID_TABLE	0x14
+#define DP_REMOTE_DPCD_READ		0x20
+#define DP_REMOTE_DPCD_WRITE		0x21
+#define DP_REMOTE_I2C_READ		0x22
+#define DP_REMOTE_I2C_WRITE		0x23
+#define DP_POWER_UP_PHY			0x24
+#define DP_POWER_DOWN_PHY		0x25
+#define DP_SINK_EVENT_NOTIFY		0x30
+#define DP_QUERY_STREAM_ENC_STATUS	0x38
+
+/* DP 1.2 MST sideband nak reasons - table 2.84 */
+#define DP_NAK_WRITE_FAILURE		0x01
+#define DP_NAK_INVALID_READ		0x02
+#define DP_NAK_CRC_FAILURE		0x03
+#define DP_NAK_BAD_PARAM		0x04
+#define DP_NAK_DEFER			0x05
+#define DP_NAK_LINK_FAILURE		0x06
+#define DP_NAK_NO_RESOURCES		0x07
+#define DP_NAK_DPCD_FAIL		0x08
+#define DP_NAK_I2C_NAK			0x09
+#define DP_NAK_ALLOCATE_FAIL		0x0a
+
 #define MODE_I2C_START	1
 #define MODE_I2C_WRITE	2
 #define MODE_I2C_READ	4
-- 
1.9.0

Re: [PATCH 01/11] drm/dp_helper: add defines for DP 1.2 and MST support.

[Todd Previte]

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> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This just adds the defines from the DP 1.2 spec, which we
> will use later.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> include/drm/drm_dp_helper.h | 78 
> +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 78 insertions(+)
>
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index cfcacec..879836d 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -37,6 +37,7 @@
> * eDP: Embedded DisplayPort version 1
> * DPI: DisplayPort Interoperability Guideline v1.1a
> * 1.2: DisplayPort 1.2
> + * MST: Multistream Transport - part of DP 1.2a
> *
> * 1.2 formally includes both eDP and DPI definitions.
> */
> @@ -103,9 +104,14 @@
> #define DP_TRAINING_AUX_RD_INTERVAL 0x00e /* XXX 1.2? */
>
> /* Multiple stream transport */
> +#define DP_FAUX_CAP 0x020 /* 1.2 */
> +# define DP_FAUX_CAP_1 (1 << 0)
> +
> #define DP_MSTM_CAP 0x021 /* 1.2 */
> # define DP_MST_CAP (1 << 0)
>
> +#define DP_GUID 0x030 /* 1.2 */
> +
> #define DP_PSR_SUPPORT 0x070 /* XXX 1.2? */
> # define DP_PSR_IS_SUPPORTED 1
> #define DP_PSR_CAPS 0x071 /* XXX 1.2? */
> @@ -221,6 +227,16 @@
> # define DP_PSR_CRC_VERIFICATION (1 << 2)
> # define DP_PSR_FRAME_CAPTURE (1 << 3)
>
> +#define DP_ADAPTER_CTRL 0x1a0
> +# define DP_ADAPTER_CTRL_FORCE_LOAD_SENSE (1 << 0)
> +
> +#define DP_BRANCH_DEVICE_CTRL 0x1a1
> +# define DP_BRANCH_DEVICE_IRQ_HPD (1 << 0)
> +
> +#define DP_PAYLOAD_ALLOCATE_SET 0x1c0
> +#define DP_PAYLOAD_ALLOCATE_START_TIME_SLOT 0x1c1
> +#define DP_PAYLOAD_ALLOCATE_TIME_SLOT_COUNT 0x1c2
> +
> #define DP_SINK_COUNT 0x200
> /* prior to 1.2 bit 7 was reserved mbz */
> # define DP_GET_SINK_COUNT(x) ((((x) & 0x80) >> 1) | ((x) & 0x3f))
> @@ -230,6 +246,9 @@
> # define DP_REMOTE_CONTROL_COMMAND_PENDING (1 << 0)
> # define DP_AUTOMATED_TEST_REQUEST (1 << 1)
> # define DP_CP_IRQ (1 << 2)
> +# define DP_MCCS_IRQ (1 << 3)
> +# define DP_DOWN_REP_MSG_RDY (1 << 4) /* DP MST */
> +# define DP_UP_REQ_MSG_RDY (1 << 5) /* DP MST */
> # define DP_SINK_SPECIFIC_IRQ (1 << 6)
>
> #define DP_LANE0_1_STATUS 0x202
> @@ -294,6 +313,13 @@
> #define DP_TEST_SINK 0x270
> #define DP_TEST_SINK_START (1 << 0)
>
> +#define DP_PAYLOAD_TABLE_UPDATE_STATUS 0x2c0 /* 1.2 MST */
> +# define DP_PAYLOAD_TABLE_UPDATED (1 << 0)
> +# define DP_PAYLOAD_ACT_HANDLED (1 << 1)
> +
> +#define DP_VC_PAYLOAD_ID_SLOT_1 0x2c1 /* 1.2 MST */
> +/* up to ID_SLOT_63 at 0x2ff */
> +
> #define DP_SOURCE_OUI 0x300
> #define DP_SINK_OUI 0x400
> #define DP_BRANCH_OUI 0x500
> @@ -303,6 +329,21 @@
> # define DP_SET_POWER_D3 0x2
> # define DP_SET_POWER_MASK 0x3
>
> +#define DP_SIDEBAND_MSG_DOWN_REQ_BASE 0x1000 /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_UP_REP_BASE 0x1200 /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_DOWN_REP_BASE 0x1400 /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_UP_REQ_BASE 0x1600 /* 1.2 MST */
> +
> +#define DP_SINK_COUNT_ESI 0x2002 /* 1.2 */
> +/* 0-5 sink count */
> +# define DP_SINK_COUNT_CP_READY (1 << 6)
> +
> +#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 0x2003 /* 1.2 */
> +
> +#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1 0x2004 /* 1.2 */
> +
> +#define DP_LINK_SERVICE_IRQ_VECTOR_ESI0 0x2005 /* 1.2 */
> +
> #define DP_PSR_ERROR_STATUS 0x2006 /* XXX 1.2? */
> # define DP_PSR_LINK_CRC_ERROR (1 << 0)
> # define DP_PSR_RFB_STORAGE_ERROR (1 << 1)
> @@ -319,6 +360,43 @@
> # define DP_PSR_SINK_INTERNAL_ERROR 7
> # define DP_PSR_SINK_STATE_MASK 0x07
>
> +/* DP 1.2 Sideband message defines */
> +/* peer device type - DP 1.2a Table 2-92 */
> +#define DP_PEER_DEVICE_NONE 0x0
> +#define DP_PEER_DEVICE_SOURCE_OR_SST 0x1
> +#define DP_PEER_DEVICE_MST_BRANCHING 0x2
> +#define DP_PEER_DEVICE_SST_SINK 0x3
> +#define DP_PEER_DEVICE_DP_LEGACY_CONV 0x4
> +
> +/* DP 1.2 MST sideband request names DP 1.2a Table 2-80 */
> +#define DP_LINK_ADDRESS 0x01
> +#define DP_CONNECTION_STATUS_NOTIFY 0x02
> +#define DP_ENUM_PATH_RESOURCES 0x10
> +#define DP_ALLOCATE_PAYLOAD 0x11
> +#define DP_QUERY_PAYLOAD 0x12
> +#define DP_RESOURCE_STATUS_NOTIFY 0x13
> +#define DP_CLEAR_PAYLOAD_ID_TABLE 0x14
> +#define DP_REMOTE_DPCD_READ 0x20
> +#define DP_REMOTE_DPCD_WRITE 0x21
> +#define DP_REMOTE_I2C_READ 0x22
> +#define DP_REMOTE_I2C_WRITE 0x23
> +#define DP_POWER_UP_PHY 0x24
> +#define DP_POWER_DOWN_PHY 0x25
> +#define DP_SINK_EVENT_NOTIFY 0x30
> +#define DP_QUERY_STREAM_ENC_STATUS 0x38
> +
> +/* DP 1.2 MST sideband nak reasons - table 2.84 */
> +#define DP_NAK_WRITE_FAILURE 0x01
> +#define DP_NAK_INVALID_READ 0x02
> +#define DP_NAK_CRC_FAILURE 0x03
> +#define DP_NAK_BAD_PARAM 0x04
> +#define DP_NAK_DEFER 0x05
> +#define DP_NAK_LINK_FAILURE 0x06
> +#define DP_NAK_NO_RESOURCES 0x07
> +#define DP_NAK_DPCD_FAIL 0x08
> +#define DP_NAK_I2C_NAK 0x09
> +#define DP_NAK_ALLOCATE_FAIL 0x0a
> +
> #define MODE_I2C_START 1
> #define MODE_I2C_WRITE 2
> #define MODE_I2C_READ 4
Constant definitions look good.

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 01/11] drm/dp_helper: add defines for DP 1.2 and MST support.

[Jingoo Han]

On Wednesday, May 21, 2014 11:55 AM, Dave Airlie wrote:
> 
> From: Dave Airlie <airlied@redhat.com>
> 
> This just adds the defines from the DP 1.2 spec, which we
> will use later.
> 
> Signed-off-by: Dave Airlie <airlied@redhat.com>

I checked this patch by using DP 1.2 spec. These definitions
are correct. Thank you.

Reviewed-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

> ---
>  include/drm/drm_dp_helper.h | 78 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 78 insertions(+)
> 
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index cfcacec..879836d 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -37,6 +37,7 @@
>   * eDP: Embedded DisplayPort version 1
>   * DPI: DisplayPort Interoperability Guideline v1.1a
>   * 1.2: DisplayPort 1.2
> + * MST: Multistream Transport - part of DP 1.2a
>   *
>   * 1.2 formally includes both eDP and DPI definitions.
>   */
> @@ -103,9 +104,14 @@
>  #define DP_TRAINING_AUX_RD_INTERVAL         0x00e   /* XXX 1.2? */
> 
>  /* Multiple stream transport */
> +#define DP_FAUX_CAP			    0x020   /* 1.2 */
> +# define DP_FAUX_CAP_1			    (1 << 0)
> +
>  #define DP_MSTM_CAP			    0x021   /* 1.2 */
>  # define DP_MST_CAP			    (1 << 0)
> 
> +#define DP_GUID				    0x030   /* 1.2 */
> +
>  #define DP_PSR_SUPPORT                      0x070   /* XXX 1.2? */
>  # define DP_PSR_IS_SUPPORTED                1
>  #define DP_PSR_CAPS                         0x071   /* XXX 1.2? */
> @@ -221,6 +227,16 @@
>  # define DP_PSR_CRC_VERIFICATION	    (1 << 2)
>  # define DP_PSR_FRAME_CAPTURE		    (1 << 3)
> 
> +#define DP_ADAPTER_CTRL			    0x1a0
> +# define DP_ADAPTER_CTRL_FORCE_LOAD_SENSE   (1 << 0)
> +
> +#define DP_BRANCH_DEVICE_CTRL		    0x1a1
> +# define DP_BRANCH_DEVICE_IRQ_HPD	    (1 << 0)
> +
> +#define DP_PAYLOAD_ALLOCATE_SET		    0x1c0
> +#define DP_PAYLOAD_ALLOCATE_START_TIME_SLOT 0x1c1
> +#define DP_PAYLOAD_ALLOCATE_TIME_SLOT_COUNT 0x1c2
> +
>  #define DP_SINK_COUNT			    0x200
>  /* prior to 1.2 bit 7 was reserved mbz */
>  # define DP_GET_SINK_COUNT(x)		    ((((x) & 0x80) >> 1) | ((x) & 0x3f))
> @@ -230,6 +246,9 @@
>  # define DP_REMOTE_CONTROL_COMMAND_PENDING  (1 << 0)
>  # define DP_AUTOMATED_TEST_REQUEST	    (1 << 1)
>  # define DP_CP_IRQ			    (1 << 2)
> +# define DP_MCCS_IRQ			    (1 << 3)
> +# define DP_DOWN_REP_MSG_RDY		    (1 << 4) /* DP MST */
> +# define DP_UP_REQ_MSG_RDY		    (1 << 5) /* DP MST */
>  # define DP_SINK_SPECIFIC_IRQ		    (1 << 6)
> 
>  #define DP_LANE0_1_STATUS		    0x202
> @@ -294,6 +313,13 @@
>  #define DP_TEST_SINK			    0x270
>  #define DP_TEST_SINK_START	    (1 << 0)
> 
> +#define DP_PAYLOAD_TABLE_UPDATE_STATUS      0x2c0   /* 1.2 MST */
> +# define DP_PAYLOAD_TABLE_UPDATED           (1 << 0)
> +# define DP_PAYLOAD_ACT_HANDLED             (1 << 1)
> +
> +#define DP_VC_PAYLOAD_ID_SLOT_1             0x2c1   /* 1.2 MST */
> +/* up to ID_SLOT_63 at 0x2ff */
> +
>  #define DP_SOURCE_OUI			    0x300
>  #define DP_SINK_OUI			    0x400
>  #define DP_BRANCH_OUI			    0x500
> @@ -303,6 +329,21 @@
>  # define DP_SET_POWER_D3                    0x2
>  # define DP_SET_POWER_MASK                  0x3
> 
> +#define DP_SIDEBAND_MSG_DOWN_REQ_BASE	    0x1000   /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_UP_REP_BASE	    0x1200   /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_DOWN_REP_BASE	    0x1400   /* 1.2 MST */
> +#define DP_SIDEBAND_MSG_UP_REQ_BASE	    0x1600   /* 1.2 MST */
> +
> +#define DP_SINK_COUNT_ESI		    0x2002   /* 1.2 */
> +/* 0-5 sink count */
> +# define DP_SINK_COUNT_CP_READY             (1 << 6)
> +
> +#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0   0x2003   /* 1.2 */
> +
> +#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1   0x2004   /* 1.2 */
> +
> +#define DP_LINK_SERVICE_IRQ_VECTOR_ESI0     0x2005   /* 1.2 */
> +
>  #define DP_PSR_ERROR_STATUS                 0x2006  /* XXX 1.2? */
>  # define DP_PSR_LINK_CRC_ERROR              (1 << 0)
>  # define DP_PSR_RFB_STORAGE_ERROR           (1 << 1)
> @@ -319,6 +360,43 @@
>  # define DP_PSR_SINK_INTERNAL_ERROR         7
>  # define DP_PSR_SINK_STATE_MASK             0x07
> 
> +/* DP 1.2 Sideband message defines */
> +/* peer device type - DP 1.2a Table 2-92 */
> +#define DP_PEER_DEVICE_NONE		0x0
> +#define DP_PEER_DEVICE_SOURCE_OR_SST	0x1
> +#define DP_PEER_DEVICE_MST_BRANCHING	0x2
> +#define DP_PEER_DEVICE_SST_SINK		0x3
> +#define DP_PEER_DEVICE_DP_LEGACY_CONV	0x4
> +
> +/* DP 1.2 MST sideband request names DP 1.2a Table 2-80 */
> +#define DP_LINK_ADDRESS			0x01
> +#define DP_CONNECTION_STATUS_NOTIFY	0x02
> +#define DP_ENUM_PATH_RESOURCES		0x10
> +#define DP_ALLOCATE_PAYLOAD		0x11
> +#define DP_QUERY_PAYLOAD		0x12
> +#define DP_RESOURCE_STATUS_NOTIFY	0x13
> +#define DP_CLEAR_PAYLOAD_ID_TABLE	0x14
> +#define DP_REMOTE_DPCD_READ		0x20
> +#define DP_REMOTE_DPCD_WRITE		0x21
> +#define DP_REMOTE_I2C_READ		0x22
> +#define DP_REMOTE_I2C_WRITE		0x23
> +#define DP_POWER_UP_PHY			0x24
> +#define DP_POWER_DOWN_PHY		0x25
> +#define DP_SINK_EVENT_NOTIFY		0x30
> +#define DP_QUERY_STREAM_ENC_STATUS	0x38
> +
> +/* DP 1.2 MST sideband nak reasons - table 2.84 */
> +#define DP_NAK_WRITE_FAILURE		0x01
> +#define DP_NAK_INVALID_READ		0x02
> +#define DP_NAK_CRC_FAILURE		0x03
> +#define DP_NAK_BAD_PARAM		0x04
> +#define DP_NAK_DEFER			0x05
> +#define DP_NAK_LINK_FAILURE		0x06
> +#define DP_NAK_NO_RESOURCES		0x07
> +#define DP_NAK_DPCD_FAIL		0x08
> +#define DP_NAK_I2C_NAK			0x09
> +#define DP_NAK_ALLOCATE_FAIL		0x0a
> +
>  #define MODE_I2C_START	1
>  #define MODE_I2C_WRITE	2
>  #define MODE_I2C_READ	4
> --
> 1.9.0

[PATCH 02/11] drm: add DP MST encoder type

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This adds an encoder type for DP MST encoders.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/drm_crtc.c  | 1 +
 include/uapi/drm/drm_mode.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index a3fe324..f1753e6 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -227,6 +227,7 @@ static const struct drm_prop_enum_list drm_encoder_enum_list[] =
 	{ DRM_MODE_ENCODER_TVDAC, "TV" },
 	{ DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
 	{ DRM_MODE_ENCODER_DSI, "DSI" },
+	{ DRM_MODE_ENCODER_DPMST, "DP MST" },
 };
 
 static const struct drm_prop_enum_list drm_subpixel_enum_list[] =
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index f104c26..719add4 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -181,6 +181,7 @@ struct drm_mode_get_plane_res {
 #define DRM_MODE_ENCODER_TVDAC	4
 #define DRM_MODE_ENCODER_VIRTUAL 5
 #define DRM_MODE_ENCODER_DSI	6
+#define DRM_MODE_ENCODER_DPMST	7
 
 struct drm_mode_get_encoder {
 	__u32 encoder_id;
-- 
1.9.0

Re: [Intel-gfx] [PATCH 02/11] drm: add DP MST encoder type

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 2136 bytes --]



> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This adds an encoder type for DP MST encoders.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/drm_crtc.c | 1 +
> include/uapi/drm/drm_mode.h | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index a3fe324..f1753e6 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -227,6 +227,7 @@ static const struct drm_prop_enum_list 
> drm_encoder_enum_list[] =
> { DRM_MODE_ENCODER_TVDAC, "TV" },
> { DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
> { DRM_MODE_ENCODER_DSI, "DSI" },
> + { DRM_MODE_ENCODER_DPMST, "DP MST" },
> };
>
> static const struct drm_prop_enum_list drm_subpixel_enum_list[] =
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index f104c26..719add4 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -181,6 +181,7 @@ struct drm_mode_get_plane_res {
> #define DRM_MODE_ENCODER_TVDAC 4
> #define DRM_MODE_ENCODER_VIRTUAL 5
> #define DRM_MODE_ENCODER_DSI 6
> +#define DRM_MODE_ENCODER_DPMST 7
>
> struct drm_mode_get_encoder {
> __u32 encoder_id;

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 03/11] drm/i915: add some registers need for displayport MST support.

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

These are just from the Haswell spec.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/i915/i915_reg.h | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8f84555..557b37a 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5386,6 +5386,7 @@ enum punit_power_well {
 #define  TRANS_DDI_EDP_INPUT_A_ONOFF	(4<<12)
 #define  TRANS_DDI_EDP_INPUT_B_ONOFF	(5<<12)
 #define  TRANS_DDI_EDP_INPUT_C_ONOFF	(6<<12)
+#define  TRANS_DDI_DP_VC_PAYLOAD_ALLOC	(1<<8)
 #define  TRANS_DDI_BFI_ENABLE		(1<<4)
 
 /* DisplayPort Transport Control */
@@ -5395,6 +5396,7 @@ enum punit_power_well {
 #define  DP_TP_CTL_ENABLE			(1<<31)
 #define  DP_TP_CTL_MODE_SST			(0<<27)
 #define  DP_TP_CTL_MODE_MST			(1<<27)
+#define  DP_TP_CTL_FORCE_ACT			(1<<25)
 #define  DP_TP_CTL_ENHANCED_FRAME_ENABLE	(1<<18)
 #define  DP_TP_CTL_FDI_AUTOTRAIN		(1<<15)
 #define  DP_TP_CTL_LINK_TRAIN_MASK		(7<<8)
@@ -5409,8 +5411,13 @@ enum punit_power_well {
 #define DP_TP_STATUS_A			0x64044
 #define DP_TP_STATUS_B			0x64144
 #define DP_TP_STATUS(port) _PORT(port, DP_TP_STATUS_A, DP_TP_STATUS_B)
-#define  DP_TP_STATUS_IDLE_DONE		(1<<25)
-#define  DP_TP_STATUS_AUTOTRAIN_DONE	(1<<12)
+#define  DP_TP_STATUS_IDLE_DONE			(1<<25)
+#define  DP_TP_STATUS_ACT_SENT			(1<<24)
+#define  DP_TP_STATUS_MODE_STATUS_MST		(1<<23)
+#define  DP_TP_STATUS_AUTOTRAIN_DONE		(1<<12)
+#define  DP_TP_STATUS_PAYLOAD_MAPPING_VC2	(3 << 8)
+#define  DP_TP_STATUS_PAYLOAD_MAPPING_VC1	(3 << 4)
+#define  DP_TP_STATUS_PAYLOAD_MAPPING_VC0	(3 << 0)
 
 /* DDI Buffer Control */
 #define DDI_BUF_CTL_A				0x64000
-- 
1.9.0

Re: [Intel-gfx] [PATCH 03/11] drm/i915: add some registers need for displayport MST support.

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 2803 bytes --]



> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> These are just from the Haswell spec.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
> b/drivers/gpu/drm/i915/i915_reg.h
> index 8f84555..557b37a 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5386,6 +5386,7 @@ enum punit_power_well {
> #define TRANS_DDI_EDP_INPUT_A_ONOFF (4<<12)
> #define TRANS_DDI_EDP_INPUT_B_ONOFF (5<<12)
> #define TRANS_DDI_EDP_INPUT_C_ONOFF (6<<12)
> +#define TRANS_DDI_DP_VC_PAYLOAD_ALLOC (1<<8)
> #define TRANS_DDI_BFI_ENABLE (1<<4)
>
> /* DisplayPort Transport Control */
> @@ -5395,6 +5396,7 @@ enum punit_power_well {
> #define DP_TP_CTL_ENABLE (1<<31)
> #define DP_TP_CTL_MODE_SST (0<<27)
> #define DP_TP_CTL_MODE_MST (1<<27)
> +#define DP_TP_CTL_FORCE_ACT (1<<25)
> #define DP_TP_CTL_ENHANCED_FRAME_ENABLE (1<<18)
> #define DP_TP_CTL_FDI_AUTOTRAIN (1<<15)
> #define DP_TP_CTL_LINK_TRAIN_MASK (7<<8)
> @@ -5409,8 +5411,13 @@ enum punit_power_well {
> #define DP_TP_STATUS_A 0x64044
> #define DP_TP_STATUS_B 0x64144
> #define DP_TP_STATUS(port) _PORT(port, DP_TP_STATUS_A, DP_TP_STATUS_B)
> -#define DP_TP_STATUS_IDLE_DONE (1<<25)
> -#define DP_TP_STATUS_AUTOTRAIN_DONE (1<<12)
> +#define DP_TP_STATUS_IDLE_DONE (1<<25)
> +#define DP_TP_STATUS_ACT_SENT (1<<24)
> +#define DP_TP_STATUS_MODE_STATUS_MST (1<<23)
> +#define DP_TP_STATUS_AUTOTRAIN_DONE (1<<12)
> +#define DP_TP_STATUS_PAYLOAD_MAPPING_VC2 (3 << 8)
> +#define DP_TP_STATUS_PAYLOAD_MAPPING_VC1 (3 << 4)
> +#define DP_TP_STATUS_PAYLOAD_MAPPING_VC0 (3 << 0)
>
> /* DDI Buffer Control */
> #define DDI_BUF_CTL_A 0x64000
Definitions look correct. If I noticed any discrepancies during testing, 
I'll flag it.

Reviewed-by: Todd Previte <tprevite@gmail.com>
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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http://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH 04/11] drm/crtc: add interface to reinitialise the legacy mode group

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This can be called to update things after dynamic connectors/encoders
are created/deleted.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/drm_crtc.c | 9 +++++++++
 include/drm/drm_crtc.h     | 1 +
 2 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index f1753e6..8bf87a6 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1421,6 +1421,15 @@ int drm_mode_group_init_legacy_group(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
 
+void drm_reinit_primary_mode_group(struct drm_device *dev)
+{
+	drm_modeset_lock_all(dev);
+	drm_mode_group_destroy(&dev->primary->mode_group);
+	drm_mode_group_init_legacy_group(dev, &dev->primary->mode_group);
+	drm_modeset_unlock_all(dev);
+}
+EXPORT_SYMBOL(drm_reinit_primary_mode_group);
+
 /**
  * drm_crtc_convert_to_umode - convert a drm_display_mode into a modeinfo
  * @out: drm_mode_modeinfo struct to return to the user
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index c6b9e8a..55bc523 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -916,6 +916,7 @@ extern const char *drm_get_tv_select_name(int val);
 extern void drm_fb_release(struct drm_file *file_priv);
 extern int drm_mode_group_init_legacy_group(struct drm_device *dev, struct drm_mode_group *group);
 extern void drm_mode_group_destroy(struct drm_mode_group *group);
+extern void drm_reinit_primary_mode_group(struct drm_device *dev);
 extern bool drm_probe_ddc(struct i2c_adapter *adapter);
 extern struct edid *drm_get_edid(struct drm_connector *connector,
 				 struct i2c_adapter *adapter);
-- 
1.9.0

Re: [PATCH 04/11] drm/crtc: add interface to reinitialise the legacy mode group

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 2725 bytes --]



> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This can be called to update things after dynamic connectors/encoders
> are created/deleted.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/drm_crtc.c | 9 +++++++++
> include/drm/drm_crtc.h | 1 +
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index f1753e6..8bf87a6 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1421,6 +1421,15 @@ int drm_mode_group_init_legacy_group(struct 
> drm_device *dev,
> }
> EXPORT_SYMBOL(drm_mode_group_init_legacy_group);
>
> +void drm_reinit_primary_mode_group(struct drm_device *dev)
> +{
> + drm_modeset_lock_all(dev);
> + drm_mode_group_destroy(&dev->primary->mode_group);
> + drm_mode_group_init_legacy_group(dev, &dev->primary->mode_group);
> + drm_modeset_unlock_all(dev);
> +}
> +EXPORT_SYMBOL(drm_reinit_primary_mode_group);
> +
> /**
> * drm_crtc_convert_to_umode - convert a drm_display_mode into a modeinfo
> * @out: drm_mode_modeinfo struct to return to the user
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index c6b9e8a..55bc523 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -916,6 +916,7 @@ extern const char *drm_get_tv_select_name(int val);
> extern void drm_fb_release(struct drm_file *file_priv);
> extern int drm_mode_group_init_legacy_group(struct drm_device *dev, 
> struct drm_mode_group *group);
> extern void drm_mode_group_destroy(struct drm_mode_group *group);
> +extern void drm_reinit_primary_mode_group(struct drm_device *dev);
> extern bool drm_probe_ddc(struct i2c_adapter *adapter);
> extern struct edid *drm_get_edid(struct drm_connector *connector,
> struct i2c_adapter *adapter);

Reviewed-by: Todd Previte <tprevite@gmail.com>
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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http://lists.freedesktop.org/mailman/listinfo/intel-gfx

[PATCH 05/11] drm/fb_helper: allow adding/removing connectors later

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This is required to get fbcon probing to work on new connectors,
callers should acquire the mode config lock before calling these.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 53 +++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_fb_helper.h     |  4 ++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 04d3fd3..a184204 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -105,6 +105,58 @@ fail:
 }
 EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
 
+int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector)
+{
+	struct drm_fb_helper_connector **temp;
+	struct drm_fb_helper_connector *fb_helper_connector;
+
+	WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+	if (fb_helper->connector_count + 1 > fb_helper->connector_info_alloc_count) {
+		temp = krealloc(fb_helper->connector_info, sizeof(struct drm_fb_helper_connector) * (fb_helper->connector_count + 1), GFP_KERNEL);
+		if (!temp)
+			return -ENOMEM;
+
+		fb_helper->connector_info_alloc_count = fb_helper->connector_count + 1;
+		fb_helper->connector_info = temp;
+	}
+
+
+	fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
+	if (!fb_helper_connector)
+		return -ENOMEM;
+
+	fb_helper_connector->connector = connector;
+	fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
+	return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
+
+int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
+				       struct drm_connector *connector)
+{
+	struct drm_fb_helper_connector *fb_helper_connector;
+	int i, j;
+
+	WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+
+	for (i = 0; i < fb_helper->connector_count; i++) {
+		if (fb_helper->connector_info[i]->connector == connector)
+			break;
+	}
+
+	if (i == fb_helper->connector_count)
+		return -EINVAL;
+	fb_helper_connector = fb_helper->connector_info[i];
+
+	for (j = i + 1; j < fb_helper->connector_count; j++) {
+		fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
+	}
+	fb_helper->connector_count--;
+	kfree(fb_helper_connector);
+	return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
+
 static int drm_fb_helper_parse_command_line(struct drm_fb_helper *fb_helper)
 {
 	struct drm_fb_helper_connector *fb_helper_conn;
@@ -534,6 +586,7 @@ int drm_fb_helper_init(struct drm_device *dev,
 		kfree(fb_helper->crtc_info);
 		return -ENOMEM;
 	}
+	fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
 	fb_helper->connector_count = 0;
 
 	for (i = 0; i < crtc_count; i++) {
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 6e622f7..4abb415 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -86,6 +86,7 @@ struct drm_fb_helper {
 	int crtc_count;
 	struct drm_fb_helper_crtc *crtc_info;
 	int connector_count;
+	int connector_info_alloc_count;
 	struct drm_fb_helper_connector **connector_info;
 	struct drm_fb_helper_funcs *funcs;
 	struct fb_info *fbdev;
@@ -128,4 +129,7 @@ struct drm_display_mode *
 drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
 		      int width, int height);
 
+int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
+int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
+				       struct drm_connector *connector);
 #endif
-- 
1.9.0

Re: [PATCH 05/11] drm/fb_helper: allow adding/removing connectors later

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 4987 bytes --]


Minor formatting issues - there's a number of lines that exceed 80 
characters in length. One other comment inline below.

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This is required to get fbcon probing to work on new connectors,
> callers should acquire the mode config lock before calling these.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/drm_fb_helper.c | 53 
> +++++++++++++++++++++++++++++++++++++++++
> include/drm/drm_fb_helper.h | 4 ++++
> 2 files changed, 57 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c 
> b/drivers/gpu/drm/drm_fb_helper.c
> index 04d3fd3..a184204 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -105,6 +105,58 @@ fail:
> }
> EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
>
> +int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, 
> struct drm_connector *connector)
> +{
> + struct drm_fb_helper_connector **temp;
> + struct drm_fb_helper_connector *fb_helper_connector;
> +
> + WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
> + if (fb_helper->connector_count + 1 > 
> fb_helper->connector_info_alloc_count) {
> + temp = krealloc(fb_helper->connector_info, sizeof(struct 
> drm_fb_helper_connector) * (fb_helper->connector_count + 1), GFP_KERNEL);
> + if (!temp)
> + return -ENOMEM;
> +
> + fb_helper->connector_info_alloc_count = fb_helper->connector_count + 1;
> + fb_helper->connector_info = temp;
> + }
> +
> +
> + fb_helper_connector = kzalloc(sizeof(struct 
> drm_fb_helper_connector), GFP_KERNEL);
> + if (!fb_helper_connector)
> + return -ENOMEM;
> +
> + fb_helper_connector->connector = connector;
> + fb_helper->connector_info[fb_helper->connector_count++] = 
> fb_helper_connector;
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
> +
> +int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
> + struct drm_connector *connector)
> +{
> + struct drm_fb_helper_connector *fb_helper_connector;
> + int i, j;
> +
> + WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
> +
> + for (i = 0; i < fb_helper->connector_count; i++) {
> + if (fb_helper->connector_info[i]->connector == connector)
> + break;
> + }
> +
> + if (i == fb_helper->connector_count)
> + return -EINVAL;
> + fb_helper_connector = fb_helper->connector_info[i];
> +
> + for (j = i + 1; j < fb_helper->connector_count; j++) {
> + fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
> + }
Why switch to using a different index variable here? Seems like you 
could just increment i and keep going...
> + fb_helper->connector_count--;
> + kfree(fb_helper_connector);
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
> +
> static int drm_fb_helper_parse_command_line(struct drm_fb_helper 
> *fb_helper)
> {
> struct drm_fb_helper_connector *fb_helper_conn;
> @@ -534,6 +586,7 @@ int drm_fb_helper_init(struct drm_device *dev,
> kfree(fb_helper->crtc_info);
> return -ENOMEM;
> }
> + fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
> fb_helper->connector_count = 0;
>
> for (i = 0; i < crtc_count; i++) {
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 6e622f7..4abb415 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -86,6 +86,7 @@ struct drm_fb_helper {
> int crtc_count;
> struct drm_fb_helper_crtc *crtc_info;
> int connector_count;
> + int connector_info_alloc_count;
> struct drm_fb_helper_connector **connector_info;
> struct drm_fb_helper_funcs *funcs;
> struct fb_info *fbdev;
> @@ -128,4 +129,7 @@ struct drm_display_mode *
> drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
> int width, int height);
>
> +int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, 
> struct drm_connector *connector);
> +int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
> + struct drm_connector *connector);
> #endif
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 06/11] drm: add a path blob property

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This property will be used by the MST code to provide userspace
with a path to parse so it can recognise connectors around hotplugs.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/drm_crtc.c | 26 ++++++++++++++++++++++++++
 include/drm/drm_crtc.h     |  5 +++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 8bf87a6..06b9255 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1165,6 +1165,7 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
 {
 	struct drm_property *edid;
 	struct drm_property *dpms;
+	struct drm_property *dev_path;
 
 	/*
 	 * Standard properties (apply to all connectors)
@@ -1179,6 +1180,12 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
 				   ARRAY_SIZE(drm_dpms_enum_list));
 	dev->mode_config.dpms_property = dpms;
 
+	dev_path = drm_property_create(dev,
+				       DRM_MODE_PROP_BLOB |
+				       DRM_MODE_PROP_IMMUTABLE,
+				       "PATH", 0);
+	dev->mode_config.path_property = dev_path;
+
 	return 0;
 }
 
@@ -3637,6 +3644,25 @@ done:
 	return ret;
 }
 
+int drm_mode_connector_set_path_property(struct drm_connector *connector,
+					 char *path)
+{
+	struct drm_device *dev = connector->dev;
+	int ret, size;
+	size = strlen(path) + 1;
+
+	connector->path_blob_ptr = drm_property_create_blob(connector->dev,
+							    size, path);
+	if (!connector->path_blob_ptr)
+		return -EINVAL;
+
+	ret = drm_object_property_set_value(&connector->base,
+					    dev->mode_config.path_property,
+					    connector->path_blob_ptr->base.id);
+	return ret;
+}
+EXPORT_SYMBOL(drm_mode_connector_set_path_property);
+
 /**
  * drm_mode_connector_update_edid_property - update the edid property of a connector
  * @connector: drm connector
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 55bc523..e33959b 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -500,6 +500,8 @@ struct drm_connector {
 	struct drm_property_blob *edid_blob_ptr;
 	struct drm_object_properties properties;
 
+	struct drm_property_blob *path_blob_ptr;
+
 	uint8_t polled; /* DRM_CONNECTOR_POLL_* */
 
 	/* requested DPMS state */
@@ -774,6 +776,7 @@ struct drm_mode_config {
 	struct list_head property_blob_list;
 	struct drm_property *edid_property;
 	struct drm_property *dpms_property;
+	struct drm_property *path_property;
 	struct drm_property *plane_type_property;
 
 	/* DVI-I properties */
@@ -926,6 +929,8 @@ extern void drm_mode_config_init(struct drm_device *dev);
 extern void drm_mode_config_reset(struct drm_device *dev);
 extern void drm_mode_config_cleanup(struct drm_device *dev);
 
+extern int drm_mode_connector_set_path_property(struct drm_connector *connector,
+						char *path);
 extern int drm_mode_connector_update_edid_property(struct drm_connector *connector,
 						struct edid *edid);
 extern int drm_object_property_set_value(struct drm_mode_object *obj,
-- 
1.9.0

Re: [Intel-gfx] [PATCH 06/11] drm: add a path blob property

[Todd Previte]

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This one looks fine to me.

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This property will be used by the MST code to provide userspace
> with a path to parse so it can recognise connectors around hotplugs.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/drm_crtc.c | 26 ++++++++++++++++++++++++++
> include/drm/drm_crtc.h | 5 +++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 8bf87a6..06b9255 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1165,6 +1165,7 @@ static int 
> drm_mode_create_standard_connector_properties(struct drm_device *dev)
> {
> struct drm_property *edid;
> struct drm_property *dpms;
> + struct drm_property *dev_path;
>
> /*
> * Standard properties (apply to all connectors)
> @@ -1179,6 +1180,12 @@ static int 
> drm_mode_create_standard_connector_properties(struct drm_device *dev)
> ARRAY_SIZE(drm_dpms_enum_list));
> dev->mode_config.dpms_property = dpms;
>
> + dev_path = drm_property_create(dev,
> + DRM_MODE_PROP_BLOB |
> + DRM_MODE_PROP_IMMUTABLE,
> + "PATH", 0);
> + dev->mode_config.path_property = dev_path;
> +
> return 0;
> }
>
> @@ -3637,6 +3644,25 @@ done:
> return ret;
> }
>
> +int drm_mode_connector_set_path_property(struct drm_connector *connector,
> + char *path)
> +{
> + struct drm_device *dev = connector->dev;
> + int ret, size;
> + size = strlen(path) + 1;
> +
> + connector->path_blob_ptr = drm_property_create_blob(connector->dev,
> + size, path);
> + if (!connector->path_blob_ptr)
> + return -EINVAL;
> +
> + ret = drm_object_property_set_value(&connector->base,
> + dev->mode_config.path_property,
> + connector->path_blob_ptr->base.id);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_mode_connector_set_path_property);
> +
> /**
> * drm_mode_connector_update_edid_property - update the edid property 
> of a connector
> * @connector: drm connector
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 55bc523..e33959b 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -500,6 +500,8 @@ struct drm_connector {
> struct drm_property_blob *edid_blob_ptr;
> struct drm_object_properties properties;
>
> + struct drm_property_blob *path_blob_ptr;
> +
> uint8_t polled; /* DRM_CONNECTOR_POLL_* */
>
> /* requested DPMS state */
> @@ -774,6 +776,7 @@ struct drm_mode_config {
> struct list_head property_blob_list;
> struct drm_property *edid_property;
> struct drm_property *dpms_property;
> + struct drm_property *path_property;
> struct drm_property *plane_type_property;
>
> /* DVI-I properties */
> @@ -926,6 +929,8 @@ extern void drm_mode_config_init(struct drm_device 
> *dev);
> extern void drm_mode_config_reset(struct drm_device *dev);
> extern void drm_mode_config_cleanup(struct drm_device *dev);
>
> +extern int drm_mode_connector_set_path_property(struct drm_connector 
> *connector,
> + char *path);
> extern int drm_mode_connector_update_edid_property(struct 
> drm_connector *connector,
> struct edid *edid);
> extern int drm_object_property_set_value(struct drm_mode_object *obj,
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 07/11] drm/helper: add Displayport multi-stream helper (v0.5)

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This is the initial import of the helper for displayport multistream.

It consists of a topology manager, init/destroy/set mst state

It supports DP 1.2 MST sideband msg protocol handler - via hpd irqs

connector detect and edid retrieval interface.

It supports i2c device over DP 1.2 sideband msg protocol (EDID reads only)

bandwidth manager API via vcpi allocation and payload updating,
along with a helper to check the ACT status.

Objects:
MST topology manager - one per toplevel MST capable GPU port - not sure if this should be higher level again
MST branch unit - one instance per plugged branching unit - one at top of hierarchy - others hanging from ports
MST port - one port per port reported by branching units, can have MST units hanging from them as well.

Changes since initial posting:
a) add a mutex responsbile for the queues, it locks the sideband and msg slots, and msgs to transmit state
b) add worker to handle connection state change events, for MST device chaining and hotplug
c) add a payload spinlock
d) add path sideband msg support
e) fixup enum path resources transmit
f) reduce max dpcd msg to 16, as per DP1.2 spec.
g) separate tx queue kicking from irq processing and move irq acking back to drivers.

Changes since v0.2:
a) reorganise code,
b) drop ACT forcing code
c) add connector naming interface using path property
d) add topology dumper helper
e) proper reference counting and lookup for ports and mstbs.
f) move tx kicking into a workq
g) add aux locking - this should be redone
h) split teardown into two parts
i) start working on documentation on interface.

Changes since v0.3:
a) vc payload locking and tracking fixes
b) add hotplug callback into driver - replaces crazy return 1 scheme
c) txmsg + mst branch device refcount fixes
d) don't bail on mst shutdown if device is gone
e) change irq handler to take all 4 bytes of SINK_COUNT + ESI vectors
f) make DP payload updates timeout longer - observed on docking station redock
g) add more info to debugfs dumper

Changes since v0.4:
a) suspend/resume support
b) more debugging in debugfs

TODO:
misc features

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 Documentation/DocBook/drm.tmpl        |    6 +
 drivers/gpu/drm/Makefile              |    2 +-
 drivers/gpu/drm/drm_dp_mst_topology.c | 2739 +++++++++++++++++++++++++++++++++
 include/drm/drm_dp_mst_helper.h       |  507 ++++++
 4 files changed, 3253 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_dp_mst_topology.c
 create mode 100644 include/drm/drm_dp_mst_helper.h

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 83dd0b0..1883976 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2296,6 +2296,12 @@ void intel_crt_init(struct drm_device *dev)
 !Edrivers/gpu/drm/drm_dp_helper.c
     </sect2>
     <sect2>
+      <title>Display Port MST Helper Functions Reference</title>
+!Pdrivers/gpu/drm/drm_dp_mst_topology.c dp mst helper
+!Iinclude/drm/drm_dp_mst_helper.h
+!Edrivers/gpu/drm/drm_dp_mst_topology.c
+    </sect2>
+    <sect2>
       <title>EDID Helper Functions Reference</title>
 !Edrivers/gpu/drm/drm_edid.c
     </sect2>
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 48e38ba..712b73e 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -23,7 +23,7 @@ drm-$(CONFIG_DRM_PANEL) += drm_panel.o
 
 drm-usb-y   := drm_usb.o
 
-drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o
+drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o drm_dp_mst_topology.o
 drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
 drm_kms_helper-$(CONFIG_DRM_KMS_FB_HELPER) += drm_fb_helper.o
 drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
new file mode 100644
index 0000000..ebd9292
--- /dev/null
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -0,0 +1,2739 @@
+/*
+ * Copyright © 2014 Red Hat
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <drm/drm_dp_mst_helper.h>
+#include <drm/drmP.h>
+
+#include <drm/drm_fixed.h>
+
+/**
+ * DOC: dp mst helper
+ *
+ * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
+ * protocol. The helpers contain a topology manager and bandwidth manager.
+ * The helpers encapsulate the sending and received of sideband msgs.
+ */
+static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
+				  char *buf);
+static int test_calc_pbn_mode(void);
+
+static void drm_dp_put_port(struct drm_dp_mst_port *port);
+
+static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
+				     int id,
+				     struct drm_dp_payload *payload);
+
+static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
+				  struct drm_dp_mst_port *port,
+				  int offset, int size, u8 *bytes);
+
+static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
+				    struct drm_dp_mst_branch *mstb);
+static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
+					   struct drm_dp_mst_branch *mstb,
+					   struct drm_dp_mst_port *port);
+static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
+				 u8 *guid);
+
+static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
+static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
+static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
+/* sideband msg handling */
+static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
+{
+	u8 bitmask = 0x80;
+	u8 bitshift = 7;
+	u8 array_index = 0;
+	int number_of_bits = num_nibbles * 4;
+	u8 remainder = 0;
+
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		remainder |= (data[array_index] & bitmask) >> bitshift;
+		bitmask >>= 1;
+		bitshift--;
+		if (bitmask == 0) {
+			bitmask = 0x80;
+			bitshift = 7;
+			array_index++;
+		}
+		if ((remainder & 0x10) == 0x10)
+			remainder ^= 0x13;
+	}
+
+	number_of_bits = 4;
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		if ((remainder & 0x10) != 0)
+			remainder ^= 0x13;
+	}
+
+	return remainder;
+}
+
+static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
+{
+	u8 bitmask = 0x80;
+	u8 bitshift = 7;
+	u8 array_index = 0;
+	int number_of_bits = number_of_bytes * 8;
+	u16 remainder = 0;
+
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		remainder |= (data[array_index] & bitmask) >> bitshift;
+		bitmask >>= 1;
+		bitshift--;
+		if (bitmask == 0) {
+			bitmask = 0x80;
+			bitshift = 7;
+			array_index++;
+		}
+		if ((remainder & 0x100) == 0x100)
+			remainder ^= 0xd5;
+	}
+
+	number_of_bits = 8;
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		if ((remainder & 0x100) != 0)
+			remainder ^= 0xd5;
+	}
+
+	return remainder & 0xff;
+}
+static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
+{
+	u8 size = 3;
+	size += (hdr->lct / 2);
+	return size;
+}
+
+static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
+					   u8 *buf, int *len)
+{
+	int idx = 0;
+	int i;
+	u8 crc4;
+	buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
+	for (i = 0; i < (hdr->lct / 2); i++)
+		buf[idx++] = hdr->rad[i];
+	buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
+		(hdr->msg_len & 0x3f);
+	buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
+
+	crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
+	buf[idx - 1] |= (crc4 & 0xf);
+
+	*len = idx;
+}
+
+static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
+					   u8 *buf, int buflen, u8 *hdrlen)
+{
+	u8 crc4;
+	u8 len;
+	int i;
+	u8 idx;
+	if (buf[0] == 0)
+		return false;
+	len = 3;
+	len += ((buf[0] & 0xf0) >> 4) / 2;
+	if (len > buflen)
+		return false;
+	crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
+
+	if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
+		DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
+		return false;
+	}
+
+	hdr->lct = (buf[0] & 0xf0) >> 4;
+	hdr->lcr = (buf[0] & 0xf);
+	idx = 1;
+	for (i = 0; i < (hdr->lct / 2); i++)
+		hdr->rad[i] = buf[idx++];
+	hdr->broadcast = (buf[idx] >> 7) & 0x1;
+	hdr->path_msg = (buf[idx] >> 6) & 0x1;
+	hdr->msg_len = buf[idx] & 0x3f;
+	idx++;
+	hdr->somt = (buf[idx] >> 7) & 0x1;
+	hdr->eomt = (buf[idx] >> 6) & 0x1;
+	hdr->seqno = (buf[idx] >> 4) & 0x1;
+	idx++;
+	*hdrlen = idx;
+	return true;
+}
+
+static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
+				       struct drm_dp_sideband_msg_tx *raw)
+{
+	int idx = 0;
+	int i;
+	u8 *buf = raw->msg;
+	buf[idx++] = req->req_type & 0x7f;
+
+	switch (req->req_type) {
+	case DP_ENUM_PATH_RESOURCES:
+		buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
+		idx++;
+		break;
+	case DP_ALLOCATE_PAYLOAD:
+		buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
+			(req->u.allocate_payload.number_sdp_streams & 0xf);
+		idx++;
+		buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
+		idx++;
+		buf[idx] = (req->u.allocate_payload.pbn >> 8);
+		idx++;
+		buf[idx] = (req->u.allocate_payload.pbn & 0xff);
+		idx++;
+		for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
+			buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
+				(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
+			idx++;
+		}
+		if (req->u.allocate_payload.number_sdp_streams & 1) {
+			i = req->u.allocate_payload.number_sdp_streams - 1;
+			buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
+			idx++;
+		}
+		break;
+	case DP_QUERY_PAYLOAD:
+		buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
+		idx++;
+		buf[idx] = (req->u.query_payload.vcpi & 0x7f);
+		idx++;
+		break;
+	case DP_REMOTE_DPCD_READ:
+		buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
+		buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
+		idx++;
+		buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
+		idx++;
+		buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
+		idx++;
+		buf[idx] = (req->u.dpcd_read.num_bytes);
+		idx++;
+		break;
+
+	case DP_REMOTE_DPCD_WRITE:
+		buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
+		buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
+		idx++;
+		buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
+		idx++;
+		buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
+		idx++;
+		buf[idx] = (req->u.dpcd_write.num_bytes);
+		idx++;
+		memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
+		idx += req->u.dpcd_write.num_bytes;
+		break;
+	case DP_REMOTE_I2C_READ:
+		buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
+		buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
+		idx++;
+		for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
+			buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
+			idx++;
+			buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
+			idx++;
+			memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
+			idx += req->u.i2c_read.transactions[i].num_bytes;
+
+			buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
+			buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
+			idx++;
+		}
+		buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
+		idx++;
+		buf[idx] = (req->u.i2c_read.num_bytes_read);
+		idx++;
+		break;
+
+	case DP_REMOTE_I2C_WRITE:
+		buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
+		idx++;
+		buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
+		idx++;
+		buf[idx] = (req->u.i2c_write.num_bytes);
+		idx++;
+		memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
+		idx += req->u.i2c_write.num_bytes;
+		break;
+	}
+	raw->cur_len = idx;
+}
+
+static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
+{
+	u8 crc4;
+	crc4 = drm_dp_msg_data_crc4(msg, len);
+	msg[len] = crc4;
+}
+
+static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
+					 struct drm_dp_sideband_msg_tx *raw)
+{
+	int idx = 0;
+	u8 *buf = raw->msg;
+
+	buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
+
+	raw->cur_len = idx;
+}
+
+/* this adds a chunk of msg to the builder to get the final msg */
+static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
+				      u8 *replybuf, u8 replybuflen, bool hdr)
+{
+	int ret;
+	u8 crc4;
+
+	if (hdr) {
+		u8 hdrlen;
+		struct drm_dp_sideband_msg_hdr recv_hdr;
+		ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
+		if (ret == false) {
+			print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
+			return false;
+		}
+
+		/* get length contained in this portion */
+		msg->curchunk_len = recv_hdr.msg_len;
+		msg->curchunk_hdrlen = hdrlen;
+
+		/* we have already gotten an somt - don't bother parsing */
+		if (recv_hdr.somt && msg->have_somt)
+			return false;
+
+		if (recv_hdr.somt) {
+			memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
+			msg->have_somt = true;
+		}
+		if (recv_hdr.eomt)
+			msg->have_eomt = true;
+
+		/* copy the bytes for the remainder of this header chunk */
+		msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
+		memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
+	} else {
+		memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
+		msg->curchunk_idx += replybuflen;
+	}
+
+	if (msg->curchunk_idx >= msg->curchunk_len) {
+		/* do CRC */
+		crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
+		/* copy chunk into bigger msg */
+		memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
+		msg->curlen += msg->curchunk_len - 1;
+	}
+	return true;
+}
+
+static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
+					       struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	int i;
+	memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
+	idx += 16;
+	repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	for (i = 0; i < repmsg->u.link_addr.nports; i++) {
+		if (raw->msg[idx] & 0x80)
+			repmsg->u.link_addr.ports[i].input_port = 1;
+
+		repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
+		repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
+
+		idx++;
+		if (idx > raw->curlen)
+			goto fail_len;
+		repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
+		repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
+		if (repmsg->u.link_addr.ports[i].input_port == 0)
+			repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
+		idx++;
+		if (idx > raw->curlen)
+			goto fail_len;
+		if (repmsg->u.link_addr.ports[i].input_port == 0) {
+			repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
+			idx++;
+			if (idx > raw->curlen)
+				goto fail_len;
+			memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
+			idx += 16;
+			if (idx > raw->curlen)
+				goto fail_len;
+			repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
+			repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
+			idx++;
+
+		}
+		if (idx > raw->curlen)
+			goto fail_len;
+	}
+
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
+						   struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
+	if (idx > raw->curlen)
+		goto fail_len;
+
+	memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
+						      struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
+						      struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+
+	repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
+	idx++;
+	/* TODO check */
+	memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
+							  struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
+	idx += 2;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
+	idx += 2;
+	if (idx > raw->curlen)
+		goto fail_len;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
+							  struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.allocate_payload.vcpi = raw->msg[idx];
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
+	idx += 2;
+	if (idx > raw->curlen)
+		goto fail_len;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
+						    struct drm_dp_sideband_msg_reply_body *repmsg)
+{
+	int idx = 1;
+	repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+	repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
+	idx += 2;
+	if (idx > raw->curlen)
+		goto fail_len;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
+					struct drm_dp_sideband_msg_reply_body *msg)
+{
+	memset(msg, 0, sizeof(*msg));
+	msg->reply_type = (raw->msg[0] & 0x80) >> 7;
+	msg->req_type = (raw->msg[0] & 0x7f);
+
+	if (msg->reply_type) {
+		memcpy(msg->u.nak.guid, &raw->msg[1], 16);
+		msg->u.nak.reason = raw->msg[17];
+		msg->u.nak.nak_data = raw->msg[18];
+		return false;
+	}
+
+	switch (msg->req_type) {
+	case DP_LINK_ADDRESS:
+		return drm_dp_sideband_parse_link_address(raw, msg);
+	case DP_QUERY_PAYLOAD:
+		return drm_dp_sideband_parse_query_payload_ack(raw, msg);
+	case DP_REMOTE_DPCD_READ:
+		return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
+	case DP_REMOTE_DPCD_WRITE:
+		return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
+	case DP_REMOTE_I2C_READ:
+		return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
+	case DP_ENUM_PATH_RESOURCES:
+		return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
+	case DP_ALLOCATE_PAYLOAD:
+		return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
+	default:
+		DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
+		return false;
+	}
+}
+
+static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
+							   struct drm_dp_sideband_msg_req_body *msg)
+{
+	int idx = 1;
+
+	msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+
+	memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
+	idx += 16;
+	if (idx > raw->curlen)
+		goto fail_len;
+
+	msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
+	msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
+	msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
+	msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
+	msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
+	idx++;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
+							   struct drm_dp_sideband_msg_req_body *msg)
+{
+	int idx = 1;
+
+	msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
+	idx++;
+	if (idx > raw->curlen)
+		goto fail_len;
+
+	memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
+	idx += 16;
+	if (idx > raw->curlen)
+		goto fail_len;
+
+	msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
+	idx++;
+	return true;
+fail_len:
+	DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
+	return false;
+}
+
+static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
+				      struct drm_dp_sideband_msg_req_body *msg)
+{
+	memset(msg, 0, sizeof(*msg));
+	msg->req_type = (raw->msg[0] & 0x7f);
+
+	switch (msg->req_type) {
+	case DP_CONNECTION_STATUS_NOTIFY:
+		return drm_dp_sideband_parse_connection_status_notify(raw, msg);
+	case DP_RESOURCE_STATUS_NOTIFY:
+		return drm_dp_sideband_parse_resource_status_notify(raw, msg);
+	default:
+		DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
+		return false;
+	}
+}
+
+static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
+{
+	struct drm_dp_sideband_msg_req_body req;
+
+	req.req_type = DP_REMOTE_DPCD_WRITE;
+	req.u.dpcd_write.port_number = port_num;
+	req.u.dpcd_write.dpcd_address = offset;
+	req.u.dpcd_write.num_bytes = num_bytes;
+	memcpy(req.u.dpcd_write.bytes, bytes, num_bytes);
+	drm_dp_encode_sideband_req(&req, msg);
+
+	return 0;
+}
+
+static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
+{
+	struct drm_dp_sideband_msg_req_body req;
+
+	req.req_type = DP_LINK_ADDRESS;
+	drm_dp_encode_sideband_req(&req, msg);
+	return 0;
+}
+
+static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
+{
+	struct drm_dp_sideband_msg_req_body req;
+
+	req.req_type = DP_ENUM_PATH_RESOURCES;
+	req.u.port_num.port_number = port_num;
+	drm_dp_encode_sideband_req(&req, msg);
+	msg->path_msg = true;
+	return 0;
+}
+
+static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
+				  u8 vcpi, uint16_t pbn)
+{
+	struct drm_dp_sideband_msg_req_body req;
+	memset(&req, 0, sizeof(req));
+	req.req_type = DP_ALLOCATE_PAYLOAD;
+	req.u.allocate_payload.port_number = port_num;
+	req.u.allocate_payload.vcpi = vcpi;
+	req.u.allocate_payload.pbn = pbn;
+	drm_dp_encode_sideband_req(&req, msg);
+	msg->path_msg = true;
+	return 0;
+}
+
+static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
+					struct drm_dp_vcpi *vcpi)
+{
+	int ret;
+
+	mutex_lock(&mgr->payload_lock);
+	ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
+	if (ret > mgr->max_payloads) {
+		ret = -EINVAL;
+		DRM_DEBUG_KMS("out of payload ids %d\n", ret);
+		goto out_unlock;
+	}
+
+	set_bit(ret, &mgr->payload_mask);
+	vcpi->vcpi = ret;
+	mgr->proposed_vcpis[ret - 1] = vcpi;
+out_unlock:
+	mutex_unlock(&mgr->payload_lock);
+	return ret;
+}
+
+static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
+				      int id)
+{
+	if (id == 0)
+		return;
+
+	mutex_lock(&mgr->payload_lock);
+	DRM_DEBUG_KMS("putting payload %d\n", id);
+	clear_bit(id, &mgr->payload_mask);
+	mgr->proposed_vcpis[id - 1] = NULL;
+	mutex_unlock(&mgr->payload_lock);
+}
+
+static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
+			      struct drm_dp_sideband_msg_tx *txmsg)
+{
+	bool ret;
+	mutex_lock(&mgr->qlock);
+	ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
+	       txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
+	mutex_unlock(&mgr->qlock);
+	return ret;
+}
+
+static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
+				    struct drm_dp_sideband_msg_tx *txmsg)
+{
+	struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
+	int ret;
+
+	ret = wait_event_timeout(mgr->tx_waitq,
+				 check_txmsg_state(mgr, txmsg),
+				 (4 * HZ));
+	mutex_lock(&mstb->mgr->qlock);
+	if (ret > 0) {
+		if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
+			ret = -EIO;
+			goto out;
+		}
+	} else {
+		DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
+
+		/* dump some state */
+		ret = -EIO;
+
+		/* remove from q */
+		if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
+		    txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
+			list_del(&txmsg->next);
+		}
+
+		if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
+		    txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
+			mstb->tx_slots[txmsg->seqno] = NULL;
+		}
+	}
+out:
+	mutex_unlock(&mgr->qlock);
+
+	return ret;
+}
+
+static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
+{
+	struct drm_dp_mst_branch *mstb;
+
+	mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
+	if (!mstb)
+		return NULL;
+
+	mstb->lct = lct;
+	if (lct > 1)
+		memcpy(mstb->rad, rad, lct / 2);
+	INIT_LIST_HEAD(&mstb->ports);
+	kref_init(&mstb->kref);
+	return mstb;
+}
+
+static void drm_dp_destroy_mst_branch_device(struct kref *kref)
+{
+	struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
+	struct drm_dp_mst_port *port, *tmp;
+	bool wake_tx = false;
+
+	cancel_work_sync(&mstb->mgr->work);
+
+	/*
+	 * destroy all ports - don't need lock
+	 * as there are no more references to the mst branch
+	 * device at this point.
+	 */
+	list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
+		list_del(&port->next);
+		drm_dp_put_port(port);
+	}
+
+	/* drop any tx slots msg */
+	mutex_lock(&mstb->mgr->qlock);
+	if (mstb->tx_slots[0]) {
+		mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
+		mstb->tx_slots[0] = NULL;
+		wake_tx = true;
+	}
+	if (mstb->tx_slots[1]) {
+		mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
+		mstb->tx_slots[1] = NULL;
+		wake_tx = true;
+	}
+	mutex_unlock(&mstb->mgr->qlock);
+
+	if (wake_tx)
+		wake_up(&mstb->mgr->tx_waitq);
+	kfree(mstb);
+}
+
+static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
+{
+	kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
+}
+
+
+static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
+{
+	switch (old_pdt) {
+	case DP_PEER_DEVICE_DP_LEGACY_CONV:
+	case DP_PEER_DEVICE_SST_SINK:
+		/* remove i2c over sideband */
+		drm_dp_mst_unregister_i2c_bus(&port->aux);
+		break;
+	case DP_PEER_DEVICE_MST_BRANCHING:
+		drm_dp_put_mst_branch_device(port->mstb);
+		port->mstb = NULL;
+		break;
+	}
+}
+
+static void drm_dp_destroy_port(struct kref *kref)
+{
+	struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
+	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
+	if (!port->input) {
+		port->vcpi.num_slots = 0;
+		if (port->connector)
+			(*port->mgr->cbs->destroy_connector)(mgr, port->connector);
+		drm_dp_port_teardown_pdt(port, port->pdt);
+
+		if (!port->input && port->vcpi.vcpi > 0)
+			drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
+	}
+	kfree(port);
+}
+
+static void drm_dp_put_port(struct drm_dp_mst_port *port)
+{
+	kref_put(&port->kref, drm_dp_destroy_port);
+}
+
+static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
+{
+	struct drm_dp_mst_port *port;
+	struct drm_dp_mst_branch *rmstb;
+	if (to_find == mstb) {
+		kref_get(&mstb->kref);
+		return mstb;
+	}
+	list_for_each_entry(port, &mstb->ports, next) {
+		if (port->mstb) {
+			rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
+			if (rmstb)
+				return rmstb;
+		}
+	}
+	return NULL;
+}
+
+static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
+{
+	struct drm_dp_mst_branch *rmstb = NULL;
+	mutex_lock(&mgr->lock);
+	if (mgr->mst_primary)
+		rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
+	mutex_unlock(&mgr->lock);
+	return rmstb;
+}
+
+static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
+{
+	struct drm_dp_mst_port *port, *mport;
+
+	list_for_each_entry(port, &mstb->ports, next) {
+		if (port == to_find) {
+			kref_get(&port->kref);
+			return port;
+		}
+		if (port->mstb) {
+			mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
+			if (mport)
+				return mport;
+		}
+	}
+	return NULL;
+}
+
+static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+{
+	struct drm_dp_mst_port *rport = NULL;
+	mutex_lock(&mgr->lock);
+	if (mgr->mst_primary)
+		rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
+	mutex_unlock(&mgr->lock);
+	return rport;
+}
+
+static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
+{
+	struct drm_dp_mst_port *port;
+
+	list_for_each_entry(port, &mstb->ports, next) {
+		if (port->port_num == port_num) {
+			kref_get(&port->kref);
+			return port;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * calculate a new RAD for this MST branch device
+ * if parent has an LCT of 2 then it has 1 nibble of RAD,
+ * if parent has an LCT of 3 then it has 2 nibbles of RAD,
+ */
+static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
+				 u8 *rad)
+{
+	int lct = port->parent->lct;
+	int shift = 4;
+	int idx = lct / 2;
+	if (lct > 1) {
+		memcpy(rad, port->parent->rad, idx);
+		shift = (lct % 2) ? 4 : 0;
+	} else
+		rad[0] = 0;
+
+	rad[idx] |= port->port_num << shift;
+	return lct + 1;
+}
+
+/*
+ * return sends link address for new mstb
+ */
+static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
+{
+	int ret;
+	u8 rad[6], lct;
+	bool send_link = false;
+	switch (port->pdt) {
+	case DP_PEER_DEVICE_DP_LEGACY_CONV:
+	case DP_PEER_DEVICE_SST_SINK:
+		/* add i2c over sideband */
+		ret = drm_dp_mst_register_i2c_bus(&port->aux);
+		break;
+	case DP_PEER_DEVICE_MST_BRANCHING:
+		lct = drm_dp_calculate_rad(port, rad);
+
+		port->mstb = drm_dp_add_mst_branch_device(lct, rad);
+		port->mstb->mgr = port->mgr;
+		port->mstb->port_parent = port;
+
+		send_link = true;
+		break;
+	}
+	return send_link;
+}
+
+static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
+				   struct drm_dp_mst_port *port)
+{
+	int ret;
+	if (port->dpcd_rev >= 0x12) {
+		port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
+		if (!port->guid_valid) {
+			ret = drm_dp_send_dpcd_write(mstb->mgr,
+						     port,
+						     DP_GUID,
+						     16, port->guid);
+			port->guid_valid = true;
+		}
+	}
+}
+
+static void build_mst_prop_path(struct drm_dp_mst_port *port,
+				struct drm_dp_mst_branch *mstb,
+				char *proppath)
+{
+	int i;
+	char temp[8];
+	snprintf(proppath, 255, "mst:%d", mstb->mgr->conn_base_id);
+	for (i = 0; i < (mstb->lct - 1); i++) {
+		int shift = (i % 2) ? 0 : 4;
+		int port_num = mstb->rad[i / 2] >> shift;
+		snprintf(temp, 8, "-%d", port_num);
+		strncat(proppath, temp, 255);
+	}
+	snprintf(temp, 8, "-%d", port->port_num);
+	strncat(proppath, temp, 255);
+}
+
+static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
+			    struct device *dev,
+			    struct drm_dp_link_addr_reply_port *port_msg)
+{
+	struct drm_dp_mst_port *port;
+	bool ret;
+	bool created = false;
+	int old_pdt = 0;
+	int old_ddps = 0;
+	port = drm_dp_get_port(mstb, port_msg->port_number);
+	if (!port) {
+		port = kzalloc(sizeof(*port), GFP_KERNEL);
+		if (!port)
+			return;
+		kref_init(&port->kref);
+		port->parent = mstb;
+		port->port_num = port_msg->port_number;
+		port->mgr = mstb->mgr;
+		port->aux.name = "DPMST";
+		port->aux.dev = dev;
+		created = true;
+	} else {
+		old_pdt = port->pdt;
+		old_ddps = port->ddps;
+	}
+
+	port->pdt = port_msg->peer_device_type;
+	port->input = port_msg->input_port;
+	port->mcs = port_msg->mcs;
+	port->ddps = port_msg->ddps;
+	port->ldps = port_msg->legacy_device_plug_status;
+	port->dpcd_rev = port_msg->dpcd_revision;
+
+	memcpy(port->guid, port_msg->peer_guid, 16);
+
+	/* manage mstb port lists with mgr lock - take a reference
+	   for this list */
+	if (created) {
+		mutex_lock(&mstb->mgr->lock);
+		kref_get(&port->kref);
+		list_add(&port->next, &mstb->ports);
+		mutex_unlock(&mstb->mgr->lock);
+	}
+
+	if (old_ddps != port->ddps) {
+		if (port->ddps) {
+			drm_dp_check_port_guid(mstb, port);
+			if (!port->input)
+				drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
+		} else {
+			port->guid_valid = false;
+			port->available_pbn = 0;
+			}
+	}
+
+	if (old_pdt != port->pdt && !port->input) {
+		drm_dp_port_teardown_pdt(port, old_pdt);
+
+		ret = drm_dp_port_setup_pdt(port);
+		if (ret == true) {
+			drm_dp_send_link_address(mstb->mgr, port->mstb);
+			port->mstb->link_address_sent = true;
+		}
+	}
+
+	if (created && !port->input) {
+		char proppath[255];
+		build_mst_prop_path(port, mstb, proppath);
+		port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
+	}
+
+	/* put reference to this port */
+	drm_dp_put_port(port);
+}
+
+static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
+			       struct drm_dp_connection_status_notify *conn_stat)
+{
+	struct drm_dp_mst_port *port;
+	int old_pdt;
+	int old_ddps;
+	bool dowork = false;
+	port = drm_dp_get_port(mstb, conn_stat->port_number);
+	if (!port)
+		return;
+
+	old_ddps = port->ddps;
+	old_pdt = port->pdt;
+	port->pdt = conn_stat->peer_device_type;
+	port->mcs = conn_stat->message_capability_status;
+	port->ldps = conn_stat->legacy_device_plug_status;
+	port->ddps = conn_stat->displayport_device_plug_status;
+
+	if (old_ddps != port->ddps) {
+		if (port->ddps) {
+			drm_dp_check_port_guid(mstb, port);
+			dowork = true;
+		} else {
+			port->guid_valid = false;
+			port->available_pbn = 0;
+		}
+	}
+	if (old_pdt != port->pdt && !port->input) {
+		drm_dp_port_teardown_pdt(port, old_pdt);
+
+		if (drm_dp_port_setup_pdt(port))
+			dowork = true;
+	}
+
+	drm_dp_put_port(port);
+	if (dowork)
+		queue_work(system_long_wq, &mstb->mgr->work);
+
+}
+
+static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
+							       u8 lct, u8 *rad)
+{
+	struct drm_dp_mst_branch *mstb;
+	struct drm_dp_mst_port *port;
+	int i;
+	/* find the port by iterating down */
+	mstb = mgr->mst_primary;
+
+	for (i = 0; i < lct - 1; i++) {
+		int shift = (i % 2) ? 0 : 4;
+		int port_num = rad[i / 2] >> shift;
+
+		list_for_each_entry(port, &mstb->ports, next) {
+			if (port->port_num == port_num) {
+				if (!port->mstb) {
+					DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
+					return NULL;
+				}
+
+				mstb = port->mstb;
+				break;
+			}
+		}
+	}
+	kref_get(&mstb->kref);
+	return mstb;
+}
+
+static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
+					       struct drm_dp_mst_branch *mstb)
+{
+	struct drm_dp_mst_port *port;
+
+	if (!mstb->link_address_sent) {
+		drm_dp_send_link_address(mgr, mstb);
+		mstb->link_address_sent = true;
+	}
+	list_for_each_entry(port, &mstb->ports, next) {
+		if (port->input)
+			continue;
+
+		if (!port->ddps)
+			continue;
+
+		if (!port->available_pbn)
+			drm_dp_send_enum_path_resources(mgr, mstb, port);
+
+		if (port->mstb)
+			drm_dp_check_and_send_link_address(mgr, port->mstb);
+	}
+}
+
+static void drm_dp_mst_link_probe_work(struct work_struct *work)
+{
+	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
+
+	drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
+
+}
+
+static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
+				 u8 *guid)
+{
+	static u8 zero_guid[16];
+
+	if (!memcmp(guid, zero_guid, 16)) {
+		u64 salt = get_jiffies_64();
+		memcpy(&guid[0], &salt, sizeof(u64));
+		memcpy(&guid[8], &salt, sizeof(u64));
+		return false;
+	}
+	return true;
+}
+
+#if 0
+static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
+{
+	struct drm_dp_sideband_msg_req_body req;
+
+	req.req_type = DP_REMOTE_DPCD_READ;
+	req.u.dpcd_read.port_number = port_num;
+	req.u.dpcd_read.dpcd_address = offset;
+	req.u.dpcd_read.num_bytes = num_bytes;
+	drm_dp_encode_sideband_req(&req, msg);
+
+	return 0;
+}
+#endif
+
+static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
+				    bool up, u8 *msg, int len)
+{
+	int ret;
+	int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
+	int tosend, total, offset;
+	int retries = 0;
+
+retry:
+	total = len;
+	offset = 0;
+	do {
+		tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
+
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
+					&msg[offset],
+					tosend);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret != tosend) {
+			if (ret == -EIO && retries < 5) {
+				retries++;
+				goto retry;
+			}
+			DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
+			WARN(1, "fail\n");
+
+			return -EIO;
+		}
+		offset += tosend;
+		total -= tosend;
+	} while (total > 0);
+	return 0;
+}
+
+static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
+				  struct drm_dp_sideband_msg_tx *txmsg)
+{
+	struct drm_dp_mst_branch *mstb = txmsg->dst;
+
+	/* both msg slots are full */
+	if (txmsg->seqno == -1) {
+		if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
+			DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
+			return -EAGAIN;
+		}
+		if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
+			txmsg->seqno = mstb->last_seqno;
+			mstb->last_seqno ^= 1;
+		} else if (mstb->tx_slots[0] == NULL)
+			txmsg->seqno = 0;
+		else
+			txmsg->seqno = 1;
+		mstb->tx_slots[txmsg->seqno] = txmsg;
+	}
+	hdr->broadcast = 0;
+	hdr->path_msg = txmsg->path_msg;
+	hdr->lct = mstb->lct;
+	hdr->lcr = mstb->lct - 1;
+	if (mstb->lct > 1)
+		memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
+	hdr->seqno = txmsg->seqno;
+	return 0;
+}
+/*
+ * process a single block of the next message in the sideband queue
+ */
+static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
+				   struct drm_dp_sideband_msg_tx *txmsg,
+				   bool up)
+{
+	u8 chunk[48];
+	struct drm_dp_sideband_msg_hdr hdr;
+	int len, space, idx, tosend;
+	int ret;
+
+	if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
+		txmsg->seqno = -1;
+		txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
+	}
+
+	/* make hdr from dst mst - for replies use seqno
+	   otherwise assign one */
+	ret = set_hdr_from_dst_qlock(&hdr, txmsg);
+	if (ret < 0)
+		return ret;
+
+	/* amount left to send in this message */
+	len = txmsg->cur_len - txmsg->cur_offset;
+
+	/* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
+	space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
+
+	tosend = min(len, space);
+	if (len == txmsg->cur_len)
+		hdr.somt = 1;
+	if (space >= len)
+		hdr.eomt = 1;
+
+
+	hdr.msg_len = tosend + 1;
+	drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
+	memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
+	/* add crc at end */
+	drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
+	idx += tosend + 1;
+
+	ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
+	if (ret) {
+		DRM_DEBUG_KMS("sideband msg failed to send\n");
+		return ret;
+	}
+
+	txmsg->cur_offset += tosend;
+	if (txmsg->cur_offset == txmsg->cur_len) {
+		txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
+		return 1;
+	}
+	return 0;
+}
+
+/* must be called holding qlock */
+static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
+{
+	struct drm_dp_sideband_msg_tx *txmsg;
+	int ret;
+
+	/* construct a chunk from the first msg in the tx_msg queue */
+	if (list_empty(&mgr->tx_msg_downq)) {
+		mgr->tx_down_in_progress = false;
+		return;
+	}
+	mgr->tx_down_in_progress = true;
+
+	txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
+	ret = process_single_tx_qlock(mgr, txmsg, false);
+	if (ret == 1) {
+		/* txmsg is sent it should be in the slots now */
+		list_del(&txmsg->next);
+	} else if (ret) {
+		DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
+		list_del(&txmsg->next);
+		if (txmsg->seqno != -1)
+			txmsg->dst->tx_slots[txmsg->seqno] = NULL;
+		txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
+		wake_up(&mgr->tx_waitq);
+	}
+	if (list_empty(&mgr->tx_msg_downq)) {
+		mgr->tx_down_in_progress = false;
+		return;
+	}
+}
+
+/* called holding qlock */
+static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
+{
+	struct drm_dp_sideband_msg_tx *txmsg;
+	int ret;
+
+	/* construct a chunk from the first msg in the tx_msg queue */
+	if (list_empty(&mgr->tx_msg_upq)) {
+		mgr->tx_up_in_progress = false;
+		return;
+	}
+
+	txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
+	ret = process_single_tx_qlock(mgr, txmsg, true);
+	if (ret == 1) {
+		/* up txmsgs aren't put in slots - so free after we send it */
+		list_del(&txmsg->next);
+		kfree(txmsg);
+	} else if (ret)
+		DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
+	mgr->tx_up_in_progress = true;
+}
+
+static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
+				 struct drm_dp_sideband_msg_tx *txmsg)
+{
+	mutex_lock(&mgr->qlock);
+	list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
+	if (!mgr->tx_down_in_progress)
+		process_single_down_tx_qlock(mgr);
+	mutex_unlock(&mgr->qlock);
+}
+
+static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
+				    struct drm_dp_mst_branch *mstb)
+{
+	int len;
+	struct drm_dp_sideband_msg_tx *txmsg;
+	int ret;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg)
+		return -ENOMEM;
+
+	txmsg->dst = mstb;
+	len = build_link_address(txmsg);
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
+	if (ret > 0) {
+		int i;
+
+		if (txmsg->reply.reply_type == 1)
+			DRM_DEBUG_KMS("link address nak received\n");
+		else {
+			DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
+			for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
+				DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d\n", i,
+				       txmsg->reply.u.link_addr.ports[i].input_port,
+				       txmsg->reply.u.link_addr.ports[i].peer_device_type,
+				       txmsg->reply.u.link_addr.ports[i].port_number,
+				       txmsg->reply.u.link_addr.ports[i].dpcd_revision,
+				       txmsg->reply.u.link_addr.ports[i].mcs,
+				       txmsg->reply.u.link_addr.ports[i].ddps,
+				       txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status);
+			}
+			for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
+				drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
+			}
+			(*mgr->cbs->hotplug)(mgr);
+		}
+	} else
+		DRM_DEBUG_KMS("link address failed %d\n", ret);
+
+	kfree(txmsg);
+	return 0;
+}
+
+static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
+					   struct drm_dp_mst_branch *mstb,
+					   struct drm_dp_mst_port *port)
+{
+	int len;
+	struct drm_dp_sideband_msg_tx *txmsg;
+	int ret;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg)
+		return -ENOMEM;
+
+	txmsg->dst = mstb;
+	len = build_enum_path_resources(txmsg, port->port_num);
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
+	if (ret > 0) {
+		if (txmsg->reply.reply_type == 1)
+			DRM_DEBUG_KMS("enum path resources nak received\n");
+		else {
+			if (port->port_num != txmsg->reply.u.path_resources.port_number)
+				DRM_ERROR("got incorrect port in response\n");
+			DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
+			       txmsg->reply.u.path_resources.avail_payload_bw_number);
+			port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
+		}
+	}
+
+	kfree(txmsg);
+	return 0;
+}
+
+int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
+			    struct drm_dp_mst_port *port,
+			    int id,
+			    int pbn)
+{
+	struct drm_dp_sideband_msg_tx *txmsg;
+	struct drm_dp_mst_branch *mstb;
+	int len, ret;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
+	if (!mstb)
+		return -EINVAL;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg) {
+		ret = -ENOMEM;
+		goto fail_put;
+	}
+
+	txmsg->dst = mstb;
+	len = build_allocate_payload(txmsg, port->port_num,
+				     id,
+				     pbn);
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
+	if (ret > 0) {
+		if (txmsg->reply.reply_type == 1) {
+			ret = -EINVAL;
+		} else
+			ret = 0;
+	}
+	kfree(txmsg);
+fail_put:
+	drm_dp_put_mst_branch_device(mstb);
+	return ret;
+}
+
+static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
+				       int id,
+				       struct drm_dp_payload *payload)
+{
+	int ret;
+
+	ret = drm_dp_dpcd_write_payload(mgr, id, payload);
+	if (ret < 0) {
+		payload->payload_state = 0;
+		return ret;
+	}
+	payload->payload_state = DP_PAYLOAD_LOCAL;
+	return 0;
+}
+
+int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
+				struct drm_dp_mst_port *port,
+				int id,
+				struct drm_dp_payload *payload)
+{
+	int ret;
+	ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
+	if (ret < 0)
+		return ret;
+	payload->payload_state = DP_PAYLOAD_REMOTE;
+	return ret;
+}
+
+int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
+				 struct drm_dp_mst_port *port,
+				 int id,
+				 struct drm_dp_payload *payload)
+{
+	DRM_DEBUG_KMS("\n");
+	/* its okay for these to fail */
+	if (port) {
+		drm_dp_payload_send_msg(mgr, port, id, 0);
+	}
+
+	drm_dp_dpcd_write_payload(mgr, id, payload);
+	payload->payload_state = 0;
+	return 0;
+}
+
+int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
+				 int id,
+				 struct drm_dp_payload *payload)
+{
+	payload->payload_state = 0;
+	return 0;
+}
+
+/**
+ * drm_dp_update_payload_part1() - Execute payload update part 1
+ * @mgr: manager to use.
+ *
+ * This iterates over all proposed virtual channels, and tries to
+ * allocate space in the link for them. For 0->slots transitions,
+ * this step just writes the VCPI to the MST device. For slots->0
+ * transitions, this writes the updated VCPIs and removes the
+ * remote VC payloads.
+ *
+ * after calling this the driver should generate ACT and payload
+ * packets.
+ */
+int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
+{
+	int i;
+	int cur_slots = 1;
+	struct drm_dp_payload req_payload;
+	struct drm_dp_mst_port *port;
+
+	mutex_lock(&mgr->payload_lock);
+	for (i = 0; i < mgr->max_payloads; i++) {
+		/* solve the current payloads - compare to the hw ones
+		   - update the hw view */
+		req_payload.start_slot = cur_slots;
+		if (mgr->proposed_vcpis[i]) {
+			port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
+			req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
+		} else {
+			port = NULL;
+			req_payload.num_slots = 0;
+		}
+		/* work out what is required to happen with this payload */
+		if (mgr->payloads[i].start_slot != req_payload.start_slot ||
+		    mgr->payloads[i].num_slots != req_payload.num_slots) {
+
+			/* need to push an update for this payload */
+			if (req_payload.num_slots) {
+				drm_dp_create_payload_step1(mgr, i + 1, &req_payload);
+				mgr->payloads[i].num_slots = req_payload.num_slots;
+			} else if (mgr->payloads[i].num_slots) {
+				mgr->payloads[i].num_slots = 0;
+				drm_dp_destroy_payload_step1(mgr, port, i + 1, &mgr->payloads[i]);
+				req_payload.payload_state = mgr->payloads[i].payload_state;
+			}
+			mgr->payloads[i].start_slot = req_payload.start_slot;
+			mgr->payloads[i].payload_state = req_payload.payload_state;
+		}
+		cur_slots += req_payload.num_slots;
+	}
+	mutex_unlock(&mgr->payload_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_update_payload_part1);
+
+/**
+ * drm_dp_update_payload_part2() - Execute payload update part 2
+ * @mgr: manager to use.
+ *
+ * This iterates over all proposed virtual channels, and tries to
+ * allocate space in the link for them. For 0->slots transitions,
+ * this step writes the remote VC payload commands. For slots->0
+ * this just resets some internal state.
+ */
+int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
+{
+	struct drm_dp_mst_port *port;
+	int i;
+	int ret;
+	mutex_lock(&mgr->payload_lock);
+	for (i = 0; i < mgr->max_payloads; i++) {
+
+		if (!mgr->proposed_vcpis[i])
+			continue;
+
+		port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
+
+		DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
+		if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
+			ret = drm_dp_create_payload_step2(mgr, port, i + 1, &mgr->payloads[i]);
+		} else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
+			ret = drm_dp_destroy_payload_step2(mgr, i + 1, &mgr->payloads[i]);
+		}
+		if (ret) {
+			mutex_unlock(&mgr->payload_lock);
+			return ret;
+		}
+	}
+	mutex_unlock(&mgr->payload_lock);
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_update_payload_part2);
+
+#if 0 /* unused as of yet */
+static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
+				 struct drm_dp_mst_port *port,
+				 int offset, int size)
+{
+	int len;
+	struct drm_dp_sideband_msg_tx *txmsg;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg)
+		return -ENOMEM;
+
+	len = build_dpcd_read(txmsg, port->port_num, 0, 8);
+	txmsg->dst = port->parent;
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	return 0;
+}
+#endif
+
+static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
+				  struct drm_dp_mst_port *port,
+				  int offset, int size, u8 *bytes)
+{
+	int len;
+	int ret;
+	struct drm_dp_sideband_msg_tx *txmsg;
+	struct drm_dp_mst_branch *mstb;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
+	if (!mstb)
+		return -EINVAL;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg) {
+		ret = -ENOMEM;
+		goto fail_put;
+	}
+
+	len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
+	txmsg->dst = mstb;
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
+	if (ret > 0) {
+		if (txmsg->reply.reply_type == 1) {
+			ret = -EINVAL;
+		} else
+			ret = 0;
+	}
+	kfree(txmsg);
+fail_put:
+	drm_dp_put_mst_branch_device(mstb);
+	return ret;
+}
+
+static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
+{
+	struct drm_dp_sideband_msg_reply_body reply;
+
+	reply.reply_type = 1;
+	reply.req_type = req_type;
+	drm_dp_encode_sideband_reply(&reply, msg);
+	return 0;
+}
+
+static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
+				    struct drm_dp_mst_branch *mstb,
+				    int req_type, int seqno, bool broadcast)
+{
+	struct drm_dp_sideband_msg_tx *txmsg;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg)
+		return -ENOMEM;
+
+	txmsg->dst = mstb;
+	txmsg->seqno = seqno;
+	drm_dp_encode_up_ack_reply(txmsg, req_type);
+
+	mutex_lock(&mgr->qlock);
+	list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
+	if (!mgr->tx_up_in_progress) {
+		process_single_up_tx_qlock(mgr);
+	}
+	mutex_unlock(&mgr->qlock);
+	return 0;
+}
+
+static int drm_dp_get_vc_payload_bw(int dp_link_bw, int dp_link_count)
+{
+	switch (dp_link_bw) {
+	case DP_LINK_BW_1_62:
+		return 3 * dp_link_count;
+	case DP_LINK_BW_2_7:
+		return 5 * dp_link_count;
+	case DP_LINK_BW_5_4:
+		return 10 * dp_link_count;
+	}
+	return 0;
+}
+
+/**
+ * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
+ * @mgr: manager to set state for
+ * @mst_state: true to enable MST on this connector - false to disable.
+ *
+ * This is called by the driver when it detects an MST capable device plugged
+ * into a DP MST capable port, or when a DP MST capable device is unplugged.
+ */
+int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
+{
+	int ret = 0;
+	struct drm_dp_mst_branch *mstb = NULL;
+
+	mutex_lock(&mgr->lock);
+	if (mst_state == mgr->mst_state)
+		goto out_unlock;
+
+	mgr->mst_state = mst_state;
+	/* set the device into MST mode */
+	if (mst_state) {
+		WARN_ON(mgr->mst_primary);
+
+		/* get dpcd info */
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret != DP_RECEIVER_CAP_SIZE) {
+			DRM_DEBUG_KMS("failed to read DPCD\n");
+			goto out_unlock;
+		}
+
+		mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
+		mgr->total_pbn = 2560;
+		mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
+		mgr->avail_slots = mgr->total_slots;
+
+		/* add initial branch device at LCT 1 */
+		mstb = drm_dp_add_mst_branch_device(1, NULL);
+		if (mstb == NULL) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+		mstb->mgr = mgr;
+
+		/* give this the main reference */
+		mgr->mst_primary = mstb;
+		kref_get(&mgr->mst_primary->kref);
+
+		{
+			struct drm_dp_payload reset_pay;
+			reset_pay.start_slot = 0;
+			reset_pay.num_slots = 0x3f;
+			drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
+		}
+
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+					 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret < 0) {
+			goto out_unlock;
+		}
+
+
+		/* sort out guid */
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret != 16) {
+			DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
+			goto out_unlock;
+		}
+
+		mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
+		if (!mgr->guid_valid) {
+			ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
+			mgr->guid_valid = true;
+		}
+
+		queue_work(system_long_wq, &mgr->work);
+
+		ret = 0;
+	} else {
+		/* disable MST on the device */
+		mstb = mgr->mst_primary;
+		mgr->mst_primary = NULL;
+		/* this can fail if the device is gone */
+		drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
+		ret = 0;
+		memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
+		mgr->payload_mask = 0;
+		set_bit(0, &mgr->payload_mask);
+	}
+
+out_unlock:
+	mutex_unlock(&mgr->lock);
+	if (mstb)
+		drm_dp_put_mst_branch_device(mstb);
+	return ret;
+
+}
+EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
+
+/**
+ * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
+ * @mgr: manager to suspend
+ *
+ * This function tells the MST device that we can't handle UP messages
+ * anymore. This should stop it from sending any since we are suspended.
+ */
+void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
+{
+	mutex_lock(&mgr->lock);
+	mutex_lock(&mgr->aux_lock);
+	drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+			   DP_MST_EN | DP_UPSTREAM_IS_SRC);
+	mutex_unlock(&mgr->aux_lock);
+	mutex_unlock(&mgr->lock);
+}
+EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
+
+/**
+ * drm_dp_mst_topology_mgr_resume() - resume the MST manager
+ * @mgr: manager to resume
+ *
+ * This will fetch DPCD and see if the device is still there,
+ * if it is, it will rewrite the MSTM control bits, and return.
+ *
+ * if the device fails this returns -1, and the driver should do
+ * a full MST reprobe, in case we were undocked.
+ */
+int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
+{
+	int ret = 0;
+
+	mutex_lock(&mgr->lock);
+
+	if (mgr->mst_primary) {
+		int sret;
+		mutex_lock(&mgr->aux_lock);
+		sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
+		mutex_unlock(&mgr->aux_lock);
+		if (sret != DP_RECEIVER_CAP_SIZE) {
+			DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
+			ret = -1;
+			goto out_unlock;
+		}
+
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+					 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret < 0) {
+			DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
+			ret = -1;
+			goto out_unlock;
+		}
+		ret = 0;
+	} else
+		ret = -1;
+
+out_unlock:
+	mutex_unlock(&mgr->lock);
+	return ret;
+}
+EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
+
+static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
+{
+	int len;
+	u8 replyblock[32];
+	int replylen, origlen, curreply;
+	int ret;
+	struct drm_dp_sideband_msg_rx *msg;
+	int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
+	msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
+
+	len = min(mgr->max_dpcd_transaction_bytes, 16);
+	mutex_lock(&mgr->aux_lock);
+	ret = drm_dp_dpcd_read(mgr->aux, basereg,
+			       replyblock, len);
+	mutex_unlock(&mgr->aux_lock);
+	if (ret != len) {
+		DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
+		return;
+	}
+	ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
+	if (!ret) {
+		DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
+		return;
+	}
+	replylen = msg->curchunk_len + msg->curchunk_hdrlen;
+
+	origlen = replylen;
+	replylen -= len;
+	curreply = len;
+	while (replylen > 0) {
+		len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
+				    replyblock, len);
+		mutex_unlock(&mgr->aux_lock);
+		if (ret != len) {
+			DRM_DEBUG_KMS("failed to read a chunk\n");
+		}
+		ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
+		if (ret == false)
+			DRM_DEBUG_KMS("failed to build sideband msg\n");
+		curreply += len;
+		replylen -= len;
+	}
+}
+
+static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
+{
+	int ret = 0;
+
+	drm_dp_get_one_sb_msg(mgr, false);
+
+	if (mgr->down_rep_recv.have_eomt) {
+		struct drm_dp_sideband_msg_tx *txmsg;
+		struct drm_dp_mst_branch *mstb;
+		int slot = -1;
+		mstb = drm_dp_get_mst_branch_device(mgr,
+						    mgr->down_rep_recv.initial_hdr.lct,
+						    mgr->down_rep_recv.initial_hdr.rad);
+
+		if (!mstb) {
+			DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
+			memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
+			return 0;
+		}
+
+		/* find the message */
+		slot = mgr->down_rep_recv.initial_hdr.seqno;
+		mutex_lock(&mgr->qlock);
+		txmsg = mstb->tx_slots[slot];
+		/* remove from slots */
+		mutex_unlock(&mgr->qlock);
+
+		if (!txmsg) {
+			DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
+			       mstb,
+			       mgr->down_rep_recv.initial_hdr.seqno,
+			       mgr->down_rep_recv.initial_hdr.lct,
+				      mgr->down_rep_recv.initial_hdr.rad[0],
+				      mgr->down_rep_recv.msg[0]);
+			drm_dp_put_mst_branch_device(mstb);
+			memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
+			return 0;
+		}
+
+		drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
+		if (txmsg->reply.reply_type == 1) {
+			DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
+		}
+
+		memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
+		drm_dp_put_mst_branch_device(mstb);
+
+		mutex_lock(&mgr->qlock);
+		txmsg->state = DRM_DP_SIDEBAND_TX_RX;
+		mstb->tx_slots[slot] = NULL;
+		mutex_unlock(&mgr->qlock);
+
+		wake_up(&mgr->tx_waitq);
+	}
+	return ret;
+}
+
+static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
+{
+	int ret = 0;
+	drm_dp_get_one_sb_msg(mgr, true);
+
+	if (mgr->up_req_recv.have_eomt) {
+		struct drm_dp_sideband_msg_req_body msg;
+		struct drm_dp_mst_branch *mstb;
+		bool seqno;
+		mstb = drm_dp_get_mst_branch_device(mgr,
+						    mgr->up_req_recv.initial_hdr.lct,
+						    mgr->up_req_recv.initial_hdr.rad);
+		if (!mstb) {
+			DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
+			memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
+			return 0;
+		}
+
+		seqno = mgr->up_req_recv.initial_hdr.seqno;
+		drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
+
+		if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
+			drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
+			drm_dp_update_port(mstb, &msg.u.conn_stat);
+			DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
+			(*mgr->cbs->hotplug)(mgr);
+
+		} else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
+			drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
+			DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
+		}
+
+		drm_dp_put_mst_branch_device(mstb);
+		memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
+	}
+	return ret;
+}
+
+/**
+ * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
+ * @mgr: manager to notify irq for.
+ * @esi: 4 bytes from SINK_COUNT_ESI
+ *
+ * This should be called from the driver when it detects a short IRQ,
+ * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
+ * topology manager will process the sideband messages received as a result
+ * of this.
+ */
+int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
+{
+	int ret = 0;
+	int sc;
+	*handled = false;
+	sc = esi[0] & 0x3f;
+	if (sc != mgr->sink_count) {
+
+		if (mgr->mst_primary && mgr->sink_count == 0 && sc) {
+			mgr->mst_primary->link_address_sent = false;
+			queue_work(system_long_wq, &mgr->work);
+		}
+		mgr->sink_count = sc;
+		*handled = true;
+
+	}
+
+	if (esi[1] & DP_DOWN_REP_MSG_RDY) {
+		ret = drm_dp_mst_handle_down_rep(mgr);
+		*handled = true;
+	}
+
+	if (esi[1] & DP_UP_REQ_MSG_RDY) {
+		ret |= drm_dp_mst_handle_up_req(mgr);
+		*handled = true;
+	}
+
+	drm_dp_mst_kick_tx(mgr);
+	return ret;
+}
+EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
+
+/**
+ * drm_dp_mst_detect_port() - get connection status for an MST port
+ * @mgr: manager for this port
+ * @port: unverified pointer to a port
+ *
+ * This returns the current connection state for a port. It validates the
+ * port pointer still exists so the caller doesn't require a reference
+ */
+enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+{
+	enum drm_connector_status status = connector_status_disconnected;
+
+	/* we need to search for the port in the mgr in case its gone */
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return connector_status_disconnected;
+
+	if (!port->ddps)
+		goto out;
+
+	switch (port->pdt) {
+	case DP_PEER_DEVICE_NONE:
+	case DP_PEER_DEVICE_MST_BRANCHING:
+		break;
+
+	case DP_PEER_DEVICE_SST_SINK:
+		status = connector_status_connected;
+		break;
+	case DP_PEER_DEVICE_DP_LEGACY_CONV:
+		if (port->ldps)
+			status = connector_status_connected;
+		break;
+	}
+out:
+	drm_dp_put_port(port);
+	return status;
+}
+EXPORT_SYMBOL(drm_dp_mst_detect_port);
+
+/**
+ * drm_dp_mst_get_edid() - get EDID for an MST port
+ * @connector: toplevel connector to get EDID for
+ * @mgr: manager for this port
+ * @port: unverified pointer to a port.
+ *
+ * This returns an EDID for the port connected to a connector,
+ * It validates the pointer still exists so the caller doesn't require a
+ * reference.
+ */
+struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+{
+	struct edid *edid = NULL;
+
+	/* we need to search for the port in the mgr in case its gone */
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return NULL;
+
+	edid = drm_get_edid(connector, &port->aux.ddc);
+	drm_dp_put_port(port);
+	return edid;
+}
+EXPORT_SYMBOL(drm_dp_mst_get_edid);
+
+/**
+ * drm_dp_find_vcpi_slots() - find slots for this PBN value
+ * @mgr: manager to use
+ * @pbn: payload bandwidth to convert into slots.
+ */
+int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
+			   int pbn)
+{
+	int num_slots;
+
+	num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
+
+	if (num_slots > mgr->avail_slots)
+		return -ENOSPC;
+	return num_slots;
+}
+EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
+
+static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
+			    struct drm_dp_vcpi *vcpi, int pbn)
+{
+	int num_slots;
+	int ret;
+
+	num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
+
+	if (num_slots > mgr->avail_slots)
+		return -ENOSPC;
+
+	vcpi->pbn = pbn;
+	vcpi->aligned_pbn = num_slots * mgr->pbn_div;
+	vcpi->num_slots = num_slots;
+
+	ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+/**
+ * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
+ * @mgr: manager for this port
+ * @port: port to allocate a virtual channel for.
+ * @pbn: payload bandwidth number to request
+ * @slots: returned number of slots for this PBN.
+ */
+bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
+{
+	int ret;
+
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return false;
+
+	if (port->vcpi.vcpi > 0) {
+		DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
+		if (pbn == port->vcpi.pbn) {
+			*slots = port->vcpi.num_slots;
+			return true;
+		}
+	}
+
+	ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
+	if (ret) {
+		DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
+		goto out;
+	}
+	DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
+	*slots = port->vcpi.num_slots;
+
+	drm_dp_put_port(port);
+	return true;
+out:
+	return false;
+}
+EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
+
+/**
+ * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
+ * @mgr: manager for this port
+ * @port: unverified pointer to a port.
+ *
+ * This just resets the number of slots for the ports VCPI for later programming.
+ */
+void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+{
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return;
+	port->vcpi.num_slots = 0;
+	drm_dp_put_port(port);
+}
+EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
+
+/**
+ * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
+ * @mgr: manager for this port
+ * @port: unverified port to deallocate vcpi for
+ */
+void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
+{
+	port = drm_dp_get_validated_port_ref(mgr, port);
+	if (!port)
+		return;
+
+	drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
+	port->vcpi.num_slots = 0;
+	port->vcpi.pbn = 0;
+	port->vcpi.aligned_pbn = 0;
+	port->vcpi.vcpi = 0;
+	drm_dp_put_port(port);
+}
+EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
+
+static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
+				     int id, struct drm_dp_payload *payload)
+{
+	u8 payload_alloc[3], status;
+	int ret;
+	int retries = 0;
+
+	mutex_lock(&mgr->aux_lock);
+	drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
+			   DP_PAYLOAD_TABLE_UPDATED);
+	mutex_unlock(&mgr->aux_lock);
+
+	payload_alloc[0] = id;
+	payload_alloc[1] = payload->start_slot;
+	payload_alloc[2] = payload->num_slots;
+
+	mutex_lock(&mgr->aux_lock);
+	ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
+	mutex_unlock(&mgr->aux_lock);
+	if (ret != 3) {
+		DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
+		goto fail;
+	}
+
+retry:
+	mutex_lock(&mgr->aux_lock);
+	ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
+	mutex_unlock(&mgr->aux_lock);
+	if (ret < 0) {
+		DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
+		goto fail;
+	}
+
+	if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
+		retries++;
+		if (retries < 20) {
+			usleep_range(10000, 20000);
+			goto retry;
+		}
+		DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
+		ret = -EINVAL;
+		goto fail;
+	}
+	ret = 0;
+fail:
+	return ret;
+}
+
+
+/**
+ * drm_dp_check_act_status() - Check ACT handled status.
+ * @mgr: manager to use
+ *
+ * Check the payload status bits in the DPCD for ACT handled completion.
+ */
+int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
+{
+	u8 status;
+	int ret;
+	int count = 0;
+
+	do {
+		mutex_lock(&mgr->aux_lock);
+		ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
+		mutex_unlock(&mgr->aux_lock);
+
+		if (ret < 0) {
+			DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
+			goto fail;
+		}
+
+		if (status & DP_PAYLOAD_ACT_HANDLED)
+			break;
+		count++;
+		udelay(100);
+
+	} while (count < 30);
+
+	if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
+		DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
+		ret = -EINVAL;
+		goto fail;
+	}
+	return 0;
+fail:
+	return ret;
+}
+EXPORT_SYMBOL(drm_dp_check_act_status);
+
+/**
+ * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
+ * @clock: dot clock for the mode
+ * @bpp: bpp for the mode.
+ *
+ * This uses the formula in the spec to calculate the PBN value for a mode.
+ */
+int drm_dp_calc_pbn_mode(int clock, int bpp)
+{
+	fixed20_12 pix_bw;
+	fixed20_12 fbpp;
+	fixed20_12 result;
+	fixed20_12 margin, tmp;
+	u32 res;
+
+	pix_bw.full = dfixed_const(clock);
+	fbpp.full = dfixed_const(bpp);
+	tmp.full = dfixed_const(8);
+	fbpp.full = dfixed_div(fbpp, tmp);
+
+	result.full = dfixed_mul(pix_bw, fbpp);
+	margin.full = dfixed_const(54);
+	tmp.full = dfixed_const(64);
+	margin.full = dfixed_div(margin, tmp);
+	result.full = dfixed_div(result, margin);
+
+	margin.full = dfixed_const(1006);
+	tmp.full = dfixed_const(1000);
+	margin.full = dfixed_div(margin, tmp);
+	result.full = dfixed_mul(result, margin);
+
+	result.full = dfixed_div(result, tmp);
+	result.full = dfixed_ceil(result);
+	res = dfixed_trunc(result);
+	return res;
+}
+EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
+
+static int test_calc_pbn_mode(void)
+{
+	int ret;
+	ret = drm_dp_calc_pbn_mode(154000, 30);
+	if (ret != 689)
+		return -EINVAL;
+	ret = drm_dp_calc_pbn_mode(234000, 30);
+	if (ret != 1047)
+		return -EINVAL;
+	return 0;
+}
+
+/* we want to kick the TX after we've ack the up/down IRQs. */
+static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
+{
+	queue_work(system_long_wq, &mgr->tx_work);
+}
+
+static void drm_dp_mst_dump_mstb(struct seq_file *m,
+				 struct drm_dp_mst_branch *mstb)
+{
+	struct drm_dp_mst_port *port;
+	int tabs = mstb->lct;
+	char prefix[10];
+	int i;
+
+	for (i = 0; i < tabs; i++)
+		prefix[i] = '\t';
+	prefix[i] = '\0';
+
+	seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
+	list_for_each_entry(port, &mstb->ports, next) {
+		seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
+		if (port->mstb)
+			drm_dp_mst_dump_mstb(m, port->mstb);
+	}
+}
+
+static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
+				  char *buf)
+{
+	int ret;
+	int i;
+	mutex_lock(&mgr->aux_lock);
+	for (i = 0; i < 4; i++) {
+		ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
+		if (ret != 16)
+			break;
+	}
+	mutex_unlock(&mgr->aux_lock);
+	if (i == 4)
+		return true;
+	return false;
+}
+
+/**
+ * drm_dp_mst_dump_topology(): dump topology to seq file.
+ * @m: seq_file to dump output to
+ * @mgr: manager to dump current topology for.
+ *
+ * helper to dump MST topology to a seq file for debugfs.
+ */
+void drm_dp_mst_dump_topology(struct seq_file *m,
+			      struct drm_dp_mst_topology_mgr *mgr)
+{
+	int i;
+	struct drm_dp_mst_port *port;
+	mutex_lock(&mgr->lock);
+	if (mgr->mst_primary)
+		drm_dp_mst_dump_mstb(m, mgr->mst_primary);
+
+	/* dump VCPIs */
+	mutex_unlock(&mgr->lock);
+
+	mutex_lock(&mgr->payload_lock);
+	seq_printf(m, "vcpi: %lx\n", mgr->payload_mask);
+
+	for (i = 0; i < mgr->max_payloads; i++) {
+		if (mgr->proposed_vcpis[i]) {
+			port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
+			seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
+		} else
+			seq_printf(m, "vcpi %d:unsed\n", i);
+	}
+	for (i = 0; i < mgr->max_payloads; i++) {
+		seq_printf(m, "payload %d: %d, %d, %d\n",
+			   i,
+			   mgr->payloads[i].payload_state,
+			   mgr->payloads[i].start_slot,
+			   mgr->payloads[i].num_slots);
+
+
+	}
+	mutex_unlock(&mgr->payload_lock);
+
+	mutex_lock(&mgr->lock);
+	if (mgr->mst_primary) {
+		u8 buf[64];
+		bool bret;
+		int ret;
+		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
+		seq_printf(m, "dpcd: ");
+		for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
+			seq_printf(m, "%02x ", buf[i]);
+		seq_printf(m, "\n");
+		ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
+		seq_printf(m, "faux/mst: ");
+		for (i = 0; i < 2; i++)
+			seq_printf(m, "%02x ", buf[i]);
+		seq_printf(m, "\n");
+		ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
+		seq_printf(m, "mst ctrl: ");
+		for (i = 0; i < 1; i++)
+			seq_printf(m, "%02x ", buf[i]);
+		seq_printf(m, "\n");
+
+		bret = dump_dp_payload_table(mgr, buf);
+		if (bret == true) {
+			seq_printf(m, "payload table: ");
+			for (i = 0; i < 63; i++)
+				seq_printf(m, "%02x ", buf[i]);
+			seq_printf(m, "\n");
+		}
+
+	}
+
+	mutex_unlock(&mgr->lock);
+
+}
+EXPORT_SYMBOL(drm_dp_mst_dump_topology);
+
+static void drm_dp_tx_work(struct work_struct *work)
+{
+	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
+
+	mutex_lock(&mgr->qlock);
+	if (mgr->tx_down_in_progress)
+		process_single_down_tx_qlock(mgr);
+	mutex_unlock(&mgr->qlock);
+}
+
+/**
+ * drm_dp_mst_topology_mgr_init - initialise a topology manager
+ * @mgr: manager struct to initialise
+ * @dev: device providing this structure - for i2c addition.
+ * @aux: DP helper aux channel to talk to this device
+ * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
+ * @max_payloads: maximum number of payloads this GPU can source
+ * @conn_base_id: the connector object ID the MST device is connected to.
+ *
+ * Return 0 for success, or negative error code on failure
+ */
+int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
+				 struct device *dev, struct drm_dp_aux *aux,
+				 int max_dpcd_transaction_bytes,
+				 int max_payloads, int conn_base_id)
+{
+	mutex_init(&mgr->lock);
+	mutex_init(&mgr->qlock);
+	mutex_init(&mgr->aux_lock);
+	mutex_init(&mgr->payload_lock);
+	INIT_LIST_HEAD(&mgr->tx_msg_upq);
+	INIT_LIST_HEAD(&mgr->tx_msg_downq);
+	INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
+	INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
+	init_waitqueue_head(&mgr->tx_waitq);
+	mgr->dev = dev;
+	mgr->aux = aux;
+	mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
+	mgr->max_payloads = max_payloads;
+	mgr->conn_base_id = conn_base_id;
+	mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
+	if (!mgr->payloads)
+		return -ENOMEM;
+	mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
+	if (!mgr->proposed_vcpis)
+		return -ENOMEM;
+	set_bit(0, &mgr->payload_mask);
+	test_calc_pbn_mode();
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
+
+/**
+ * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
+ * @mgr: manager to destroy
+ */
+void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
+{
+	mutex_lock(&mgr->payload_lock);
+	kfree(mgr->payloads);
+	mgr->payloads = NULL;
+	kfree(mgr->proposed_vcpis);
+	mgr->proposed_vcpis = NULL;
+	mutex_unlock(&mgr->payload_lock);
+	mgr->dev = NULL;
+	mgr->aux = NULL;
+}
+EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
+
+/* I2C device */
+static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
+			       int num)
+{
+	struct drm_dp_aux *aux = adapter->algo_data;
+	struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
+	struct drm_dp_mst_branch *mstb;
+	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
+	unsigned int i;
+	bool reading = false;
+	struct drm_dp_sideband_msg_req_body msg;
+	struct drm_dp_sideband_msg_tx *txmsg = NULL;
+	int ret;
+
+	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
+	if (!mstb)
+		return -EREMOTEIO;
+
+	/* construct i2c msg */
+	/* see if last msg is a read */
+	if (msgs[num - 1].flags & I2C_M_RD)
+		reading = true;
+
+	if (!reading) {
+		DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
+		ret = -EIO;
+		goto out;
+	}
+
+	msg.req_type = DP_REMOTE_I2C_READ;
+	msg.u.i2c_read.num_transactions = num - 1;
+	msg.u.i2c_read.port_number = port->port_num;
+	for (i = 0; i < num - 1; i++) {
+		msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
+		msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
+		memcpy(&msg.u.i2c_read.transactions[i].bytes, msgs[i].buf, msgs[i].len);
+	}
+	msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
+	msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
+
+	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+	if (!txmsg) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	txmsg->dst = mstb;
+	drm_dp_encode_sideband_req(&msg, txmsg);
+
+	drm_dp_queue_down_tx(mgr, txmsg);
+
+	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
+	if (ret > 0) {
+
+		if (txmsg->reply.reply_type == 1) { /* got a NAK back */
+			ret = -EREMOTEIO;
+			goto out;
+		}
+		if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
+			ret = -EIO;
+			goto out;
+		}
+		memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
+		ret = num;
+	}
+out:
+	kfree(txmsg);
+	drm_dp_put_mst_branch_device(mstb);
+	return ret;
+}
+
+static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+	       I2C_FUNC_SMBUS_READ_BLOCK_DATA |
+	       I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
+	       I2C_FUNC_10BIT_ADDR;
+}
+
+static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
+	.functionality = drm_dp_mst_i2c_functionality,
+	.master_xfer = drm_dp_mst_i2c_xfer,
+};
+
+/**
+ * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
+ * @aux: DisplayPort AUX channel
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
+{
+	aux->ddc.algo = &drm_dp_mst_i2c_algo;
+	aux->ddc.algo_data = aux;
+	aux->ddc.retries = 3;
+
+	aux->ddc.class = I2C_CLASS_DDC;
+	aux->ddc.owner = THIS_MODULE;
+	aux->ddc.dev.parent = aux->dev;
+	aux->ddc.dev.of_node = aux->dev->of_node;
+
+	strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
+		sizeof(aux->ddc.name));
+
+	return i2c_add_adapter(&aux->ddc);
+}
+
+/**
+ * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
+ * @aux: DisplayPort AUX channel
+ */
+static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
+{
+	i2c_del_adapter(&aux->ddc);
+}
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
new file mode 100644
index 0000000..6626d1b
--- /dev/null
+++ b/include/drm/drm_dp_mst_helper.h
@@ -0,0 +1,507 @@
+/*
+ * Copyright © 2014 Red Hat.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+#ifndef _DRM_DP_MST_HELPER_H_
+#define _DRM_DP_MST_HELPER_H_
+
+#include <linux/types.h>
+#include <drm/drm_dp_helper.h>
+
+struct drm_dp_mst_branch;
+
+/**
+ * struct drm_dp_vcpi - Virtual Channel Payload Identifer
+ * @vcpi: Virtual channel ID.
+ * @pbn: Payload Bandwidth Number for this channel
+ * @aligned_pbn: PBN aligned with slot size
+ * @num_slots: number of slots for this PBN
+ */
+struct drm_dp_vcpi {
+	int vcpi;
+	int pbn;
+	int aligned_pbn;
+	int num_slots;
+};
+
+/**
+ * struct drm_dp_mst_port - MST port
+ * @kref: reference count for this port.
+ * @guid_valid: for DP 1.2 devices if we have validated the GUID.
+ * @guid: guid for DP 1.2 device on this port.
+ * @port_num: port number
+ * @input: if this port is an input port.
+ * @mcs: message capability status - DP 1.2 spec.
+ * @ddps: DisplayPort Device Plug Status - DP 1.2
+ * @pdt: Peer Device Type
+ * @ldps: Legacy Device Plug Status
+ * @dpcd_rev: DPCD revision of device on this port
+ * @available_pbn: Available bandwidth for this port.
+ * @next: link to next port on this branch device
+ * @mstb: branch device attach below this port
+ * @aux: i2c aux transport to talk to device connected to this port.
+ * @parent: branch device parent of this port
+ * @vcpi: Virtual Channel Payload info for this port.
+ * @connector: DRM connector this port is connected to.
+ * @mgr: topology manager this port lives under.
+ *
+ * This structure represents an MST port endpoint on a device somewhere
+ * in the MST topology.
+ */
+struct drm_dp_mst_port {
+	struct kref kref;
+
+	/* if dpcd 1.2 device is on this port - its GUID info */
+	bool guid_valid;
+	u8 guid[16];
+
+	u8 port_num;
+	bool input;
+	bool mcs;
+	bool ddps;
+	u8 pdt;
+	bool ldps;
+	u8 dpcd_rev;
+	uint16_t available_pbn;
+	struct list_head next;
+	struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */
+	struct drm_dp_aux aux; /* i2c bus for this port? */
+	struct drm_dp_mst_branch *parent;
+
+	struct drm_dp_vcpi vcpi;
+	struct drm_connector *connector;
+	struct drm_dp_mst_topology_mgr *mgr;
+};
+
+/**
+ * struct drm_dp_mst_branch - MST branch device.
+ * @kref: reference count for this port.
+ * @rad: Relative Address to talk to this branch device.
+ * @lct: Link count total to talk to this branch device.
+ * @num_ports: number of ports on the branch.
+ * @msg_slots: one bit per transmitted msg slot.
+ * @ports: linked list of ports on this branch.
+ * @port_parent: pointer to the port parent, NULL if toplevel.
+ * @mgr: topology manager for this branch device.
+ * @tx_slots: transmission slots for this device.
+ * @last_seqno: last sequence number used to talk to this.
+ * @link_address_sent: if a link address message has been sent to this device yet.
+ *
+ * This structure represents an MST branch device, there is one
+ * primary branch device at the root, along with any others connected
+ * to downstream ports
+ */
+struct drm_dp_mst_branch {
+	struct kref kref;
+	u8 rad[8];
+	u8 lct;
+	int num_ports;
+
+	int msg_slots;
+	struct list_head ports;
+
+	/* list of tx ops queue for this port */
+	struct drm_dp_mst_port *port_parent;
+	struct drm_dp_mst_topology_mgr *mgr;
+
+	/* slots are protected by mstb->mgr->qlock */
+	struct drm_dp_sideband_msg_tx *tx_slots[2];
+	int last_seqno;
+	bool link_address_sent;
+};
+
+
+/* sideband msg header - not bit struct */
+struct drm_dp_sideband_msg_hdr {
+	u8 lct;
+	u8 lcr;
+	u8 rad[8];
+	bool broadcast;
+	bool path_msg;
+	u8 msg_len;
+	bool somt;
+	bool eomt;
+	bool seqno;
+};
+
+struct drm_dp_nak_reply {
+	u8 guid[16];
+	u8 reason;
+	u8 nak_data;
+};
+
+struct drm_dp_link_address_ack_reply {
+	u8 guid[16];
+	u8 nports;
+	struct drm_dp_link_addr_reply_port {
+		bool input_port;
+		u8 peer_device_type;
+		u8 port_number;
+		bool mcs;
+		bool ddps;
+		bool legacy_device_plug_status;
+		u8 dpcd_revision;
+		u8 peer_guid[16];
+		bool num_sdp_streams;
+		bool num_sdp_stream_sinks;
+	} ports[16];
+};
+
+struct drm_dp_remote_dpcd_read_ack_reply {
+	u8 port_number;
+	u8 num_bytes;
+	u8 bytes[255];
+};
+
+struct drm_dp_remote_dpcd_write_ack_reply {
+	u8 port_number;
+};
+
+struct drm_dp_remote_dpcd_write_nak_reply {
+	u8 port_number;
+	u8 reason;
+	u8 bytes_written_before_failure;
+};
+
+struct drm_dp_remote_i2c_read_ack_reply {
+	u8 port_number;
+	u8 num_bytes;
+	u8 bytes[255];
+};
+
+struct drm_dp_remote_i2c_read_nak_reply {
+	u8 port_number;
+	u8 nak_reason;
+	u8 i2c_nak_transaction;
+};
+
+struct drm_dp_remote_i2c_write_ack_reply {
+	u8 port_number;
+};
+
+
+struct drm_dp_sideband_msg_rx {
+	u8 chunk[48];
+	u8 msg[256];
+	u8 curchunk_len;
+	u8 curchunk_idx; /* chunk we are parsing now */
+	u8 curchunk_hdrlen;
+	u8 curlen; /* total length of the msg */
+	bool have_somt;
+	bool have_eomt;
+	struct drm_dp_sideband_msg_hdr initial_hdr;
+};
+
+
+struct drm_dp_allocate_payload {
+	u8 port_number;
+	u8 number_sdp_streams;
+	u8 vcpi;
+	u16 pbn;
+	u8 sdp_stream_sink[8];
+};
+
+struct drm_dp_allocate_payload_ack_reply {
+	u8 port_number;
+	u8 vcpi;
+	u16 allocated_pbn;
+};
+
+struct drm_dp_connection_status_notify {
+	u8 guid[16];
+	u8 port_number;
+	bool legacy_device_plug_status;
+	bool displayport_device_plug_status;
+	bool message_capability_status;
+	bool input_port;
+	u8 peer_device_type;
+};
+
+struct drm_dp_remote_dpcd_read {
+	u8 port_number;
+	u32 dpcd_address;
+	u8 num_bytes;
+};
+
+struct drm_dp_remote_dpcd_write {
+	u8 port_number;
+	u32 dpcd_address;
+	u8 num_bytes;
+	u8 bytes[255];
+};
+
+struct drm_dp_remote_i2c_read {
+	u8 num_transactions;
+	u8 port_number;
+	struct {
+		u8 i2c_dev_id;
+		u8 num_bytes;
+		u8 bytes[255];
+		u8 no_stop_bit;
+		u8 i2c_transaction_delay;
+	} transactions[4];
+	u8 read_i2c_device_id;
+	u8 num_bytes_read;
+};
+
+struct drm_dp_remote_i2c_write {
+	u8 port_number;
+	u8 write_i2c_device_id;
+	u8 num_bytes;
+	u8 bytes[255];
+};
+
+/* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
+struct drm_dp_port_number_req {
+	u8 port_number;
+};
+
+struct drm_dp_enum_path_resources_ack_reply {
+	u8 port_number;
+	u16 full_payload_bw_number;
+	u16 avail_payload_bw_number;
+};
+
+/* covers POWER_DOWN_PHY, POWER_UP_PHY */
+struct drm_dp_port_number_rep {
+	u8 port_number;
+};
+
+struct drm_dp_query_payload {
+	u8 port_number;
+	u8 vcpi;
+};
+
+struct drm_dp_resource_status_notify {
+	u8 port_number;
+	u8 guid[16];
+	u16 available_pbn;
+};
+
+struct drm_dp_query_payload_ack_reply {
+	u8 port_number;
+	u8 allocated_pbn;
+};
+
+struct drm_dp_sideband_msg_req_body {
+	u8 req_type;
+	union ack_req {
+		struct drm_dp_connection_status_notify conn_stat;
+		struct drm_dp_port_number_req port_num;
+		struct drm_dp_resource_status_notify resource_stat;
+
+		struct drm_dp_query_payload query_payload;
+		struct drm_dp_allocate_payload allocate_payload;
+
+		struct drm_dp_remote_dpcd_read dpcd_read;
+		struct drm_dp_remote_dpcd_write dpcd_write;
+
+		struct drm_dp_remote_i2c_read i2c_read;
+		struct drm_dp_remote_i2c_write i2c_write;
+	} u;
+};
+
+struct drm_dp_sideband_msg_reply_body {
+	u8 reply_type;
+	u8 req_type;
+	union ack_replies {
+		struct drm_dp_nak_reply nak;
+		struct drm_dp_link_address_ack_reply link_addr;
+		struct drm_dp_port_number_rep port_number;
+
+		struct drm_dp_enum_path_resources_ack_reply path_resources;
+		struct drm_dp_allocate_payload_ack_reply allocate_payload;
+		struct drm_dp_query_payload_ack_reply query_payload;
+
+		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
+		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
+		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
+
+		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
+		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
+		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
+	} u;
+};
+
+/* msg is queued to be put into a slot */
+#define DRM_DP_SIDEBAND_TX_QUEUED 0
+/* msg has started transmitting on a slot - still on msgq */
+#define DRM_DP_SIDEBAND_TX_START_SEND 1
+/* msg has finished transmitting on a slot - removed from msgq only in slot */
+#define DRM_DP_SIDEBAND_TX_SENT 2
+/* msg has received a response - removed from slot */
+#define DRM_DP_SIDEBAND_TX_RX 3
+#define DRM_DP_SIDEBAND_TX_TIMEOUT 4
+
+struct drm_dp_sideband_msg_tx {
+	u8 msg[256];
+	u8 chunk[48];
+	u8 cur_offset;
+	u8 cur_len;
+	struct drm_dp_mst_branch *dst;
+	struct list_head next;
+	int seqno;
+	int state;
+	bool path_msg;
+	struct drm_dp_sideband_msg_reply_body reply;
+};
+
+/* sideband msg handler */
+struct drm_dp_mst_topology_mgr;
+struct drm_dp_mst_topology_cbs {
+	/* create a connector for a port */
+	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *path);
+	void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
+				  struct drm_connector *connector);
+	void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);
+
+};
+
+#define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)
+
+#define DP_PAYLOAD_LOCAL 1
+#define DP_PAYLOAD_REMOTE 2
+#define DP_PAYLOAD_DELETE_LOCAL 3
+
+struct drm_dp_payload {
+	int payload_state;
+	int start_slot;
+	int num_slots;
+};
+
+/**
+ * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
+ * @dev: device pointer for adding i2c devices etc.
+ * @cbs: callbacks for connector addition and destruction.
+ * @max_dpcd_transaction_bytes - maximum number of bytes to read/write in one go.
+ * @aux: aux channel for the DP connector.
+ * @max_payloads: maximum number of payloads the GPU can generate.
+ * @conn_base_id: DRM connector ID this mgr is connected to.
+ * @down_rep_recv: msg receiver state for down replies.
+ * @up_req_recv: msg receiver state for up requests.
+ * @lock: protects mst state, primary, guid, dpcd.
+ * @aux_lock: protects aux channel.
+ * @mst_state: if this manager is enabled for an MST capable port.
+ * @mst_primary: pointer to the primary branch device.
+ * @guid_valid: GUID valid for the primary branch device.
+ * @guid: GUID for primary port.
+ * @dpcd: cache of DPCD for primary port.
+ * @pbn_div: PBN to slots divisor.
+ *
+ * This struct represents the toplevel displayport MST topology manager.
+ * There should be one instance of this for every MST capable DP connector
+ * on the GPU.
+ */
+struct drm_dp_mst_topology_mgr {
+
+	struct device *dev;
+	struct drm_dp_mst_topology_cbs *cbs;
+	int max_dpcd_transaction_bytes;
+	struct drm_dp_aux *aux; /* auxch for this topology mgr to use */
+	int max_payloads;
+	int conn_base_id;
+
+	/* only ever accessed from the workqueue - which should be serialised */
+	struct drm_dp_sideband_msg_rx down_rep_recv;
+	struct drm_dp_sideband_msg_rx up_req_recv;
+
+	/* pointer to info about the initial MST device */
+	struct mutex lock; /* protects mst_state + primary + guid + dpcd */
+
+	struct mutex aux_lock; /* protect access to the AUX */
+	bool mst_state;
+	struct drm_dp_mst_branch *mst_primary;
+	/* primary MST device GUID */
+	bool guid_valid;
+	u8 guid[16];
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+	u8 sink_count;
+	int pbn_div;
+	int total_slots;
+	int avail_slots;
+	int total_pbn;
+
+	/* messages to be transmitted */
+	/* qlock protects the upq/downq and in_progress,
+	   the mstb tx_slots and txmsg->state once they are queued */
+	struct mutex qlock;
+	struct list_head tx_msg_downq;
+	struct list_head tx_msg_upq;
+	bool tx_down_in_progress;
+	bool tx_up_in_progress;
+
+	/* payload info + lock for it */
+	struct mutex payload_lock;
+	struct drm_dp_vcpi **proposed_vcpis;
+	struct drm_dp_payload *payloads;
+	unsigned long payload_mask;
+
+	wait_queue_head_t tx_waitq;
+	struct work_struct work;
+
+	struct work_struct tx_work;
+};
+
+int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, struct device *dev, struct drm_dp_aux *aux, int max_dpcd_transaction_bytes, int max_payloads, int conn_base_id);
+
+void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
+
+
+int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
+
+
+int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
+
+
+enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+
+struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+
+
+int drm_dp_calc_pbn_mode(int clock, int bpp);
+
+
+bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots);
+
+
+void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+
+
+void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
+				struct drm_dp_mst_port *port);
+
+
+int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
+			   int pbn);
+
+
+int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);
+
+
+int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);
+
+int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
+
+void drm_dp_mst_dump_topology(struct seq_file *m,
+			      struct drm_dp_mst_topology_mgr *mgr);
+
+void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
+int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
+#endif
-- 
1.9.0

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Re: [PATCH 07/11] drm/helper: add Displayport multi-stream helper (v0.5)

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 106365 bytes --]


This patch is a monster, but that's to be expected with MST, I suppose. 
:) It has some formatting issues (lines over 80 characters in length) 
but that can be cleaned up later (as far as I'm concerned). Otherwise I 
don't see anything glaring here, so...

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:55 PM
> From: Dave Airlie <airlied@redhat.com>
>
> This is the initial import of the helper for displayport multistream.
>
> It consists of a topology manager, init/destroy/set mst state
>
> It supports DP 1.2 MST sideband msg protocol handler - via hpd irqs
>
> connector detect and edid retrieval interface.
>
> It supports i2c device over DP 1.2 sideband msg protocol (EDID reads only)
>
> bandwidth manager API via vcpi allocation and payload updating,
> along with a helper to check the ACT status.
>
> Objects:
> MST topology manager - one per toplevel MST capable GPU port - not 
> sure if this should be higher level again
> MST branch unit - one instance per plugged branching unit - one at top 
> of hierarchy - others hanging from ports
> MST port - one port per port reported by branching units, can have MST 
> units hanging from them as well.
>
> Changes since initial posting:
> a) add a mutex responsbile for the queues, it locks the sideband and 
> msg slots, and msgs to transmit state
> b) add worker to handle connection state change events, for MST device 
> chaining and hotplug
> c) add a payload spinlock
> d) add path sideband msg support
> e) fixup enum path resources transmit
> f) reduce max dpcd msg to 16, as per DP1.2 spec.
> g) separate tx queue kicking from irq processing and move irq acking 
> back to drivers.
>
> Changes since v0.2:
> a) reorganise code,
> b) drop ACT forcing code
> c) add connector naming interface using path property
> d) add topology dumper helper
> e) proper reference counting and lookup for ports and mstbs.
> f) move tx kicking into a workq
> g) add aux locking - this should be redone
> h) split teardown into two parts
> i) start working on documentation on interface.
>
> Changes since v0.3:
> a) vc payload locking and tracking fixes
> b) add hotplug callback into driver - replaces crazy return 1 scheme
> c) txmsg + mst branch device refcount fixes
> d) don't bail on mst shutdown if device is gone
> e) change irq handler to take all 4 bytes of SINK_COUNT + ESI vectors
> f) make DP payload updates timeout longer - observed on docking 
> station redock
> g) add more info to debugfs dumper
>
> Changes since v0.4:
> a) suspend/resume support
> b) more debugging in debugfs
>
> TODO:
> misc features
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> Documentation/DocBook/drm.tmpl | 6 +
> drivers/gpu/drm/Makefile | 2 +-
> drivers/gpu/drm/drm_dp_mst_topology.c | 2739 
> +++++++++++++++++++++++++++++++++
> include/drm/drm_dp_mst_helper.h | 507 ++++++
> 4 files changed, 3253 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/drm_dp_mst_topology.c
> create mode 100644 include/drm/drm_dp_mst_helper.h
>
> diff --git a/Documentation/DocBook/drm.tmpl 
> b/Documentation/DocBook/drm.tmpl
> index 83dd0b0..1883976 100644
> --- a/Documentation/DocBook/drm.tmpl
> +++ b/Documentation/DocBook/drm.tmpl
> @@ -2296,6 +2296,12 @@ void intel_crt_init(struct drm_device *dev)
> !Edrivers/gpu/drm/drm_dp_helper.c
> </sect2>
> <sect2>
> + <title>Display Port MST Helper Functions Reference</title>
> +!Pdrivers/gpu/drm/drm_dp_mst_topology.c dp mst helper
> +!Iinclude/drm/drm_dp_mst_helper.h
> +!Edrivers/gpu/drm/drm_dp_mst_topology.c
> + </sect2>
> + <sect2>
> <title>EDID Helper Functions Reference</title>
> !Edrivers/gpu/drm/drm_edid.c
> </sect2>
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 48e38ba..712b73e 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -23,7 +23,7 @@ drm-$(CONFIG_DRM_PANEL) += drm_panel.o
>
> drm-usb-y := drm_usb.o
>
> -drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o
> +drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o 
> drm_probe_helper.o drm_dp_mst_topology.o
> drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
> drm_kms_helper-$(CONFIG_DRM_KMS_FB_HELPER) += drm_fb_helper.o
> drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c 
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> new file mode 100644
> index 0000000..ebd9292
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -0,0 +1,2739 @@
> +/*
> + * Copyright © 2014 Red Hat
> + *
> + * Permission to use, copy, modify, distribute, and sell this 
> software and its
> + * documentation for any purpose is hereby granted without fee, 
> provided that
> + * the above copyright notice appear in all copies and that both that 
> copyright
> + * notice and this permission notice appear in supporting 
> documentation, and
> + * that the name of the copyright holders not be used in advertising or
> + * publicity pertaining to distribution of the software without specific,
> + * written prior permission. The copyright holders make no 
> representations
> + * about the suitability of this software for any purpose. It is 
> provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS 
> SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, 
> INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 
> LOSS OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
> PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/errno.h>
> +#include <linux/sched.h>
> +#include <linux/i2c.h>
> +#include <drm/drm_dp_mst_helper.h>
> +#include <drm/drmP.h>
> +
> +#include <drm/drm_fixed.h>
> +
> +/**
> + * DOC: dp mst helper
> + *
> + * These functions contain parts of the DisplayPort 1.2a MultiStream 
> Transport
> + * protocol. The helpers contain a topology manager and bandwidth 
> manager.
> + * The helpers encapsulate the sending and received of sideband msgs.
> + */
> +static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
> + char *buf);
> +static int test_calc_pbn_mode(void);
> +
> +static void drm_dp_put_port(struct drm_dp_mst_port *port);
> +
> +static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
> + int id,
> + struct drm_dp_payload *payload);
> +
> +static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int offset, int size, u8 *bytes);
> +
> +static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb);
> +static int drm_dp_send_enum_path_resources(struct 
> drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb,
> + struct drm_dp_mst_port *port);
> +static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
> + u8 *guid);
> +
> +static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
> +static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
> +static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
> +/* sideband msg handling */
> +static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
> +{
> + u8 bitmask = 0x80;
> + u8 bitshift = 7;
> + u8 array_index = 0;
> + int number_of_bits = num_nibbles * 4;
> + u8 remainder = 0;
> +
> + while (number_of_bits != 0) {
> + number_of_bits--;
> + remainder <<= 1;
> + remainder |= (data[array_index] & bitmask) >> bitshift;
> + bitmask >>= 1;
> + bitshift--;
> + if (bitmask == 0) {
> + bitmask = 0x80;
> + bitshift = 7;
> + array_index++;
> + }
> + if ((remainder & 0x10) == 0x10)
> + remainder ^= 0x13;
> + }
> +
> + number_of_bits = 4;
> + while (number_of_bits != 0) {
> + number_of_bits--;
> + remainder <<= 1;
> + if ((remainder & 0x10) != 0)
> + remainder ^= 0x13;
> + }
> +
> + return remainder;
> +}
> +
> +static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
> +{
> + u8 bitmask = 0x80;
> + u8 bitshift = 7;
> + u8 array_index = 0;
> + int number_of_bits = number_of_bytes * 8;
> + u16 remainder = 0;
> +
> + while (number_of_bits != 0) {
> + number_of_bits--;
> + remainder <<= 1;
> + remainder |= (data[array_index] & bitmask) >> bitshift;
> + bitmask >>= 1;
> + bitshift--;
> + if (bitmask == 0) {
> + bitmask = 0x80;
> + bitshift = 7;
> + array_index++;
> + }
> + if ((remainder & 0x100) == 0x100)
> + remainder ^= 0xd5;
> + }
> +
> + number_of_bits = 8;
> + while (number_of_bits != 0) {
> + number_of_bits--;
> + remainder <<= 1;
> + if ((remainder & 0x100) != 0)
>
> + remainder ^= 0xd5;
> + }
> +
> + return remainder & 0xff;
> +}
> +static inline u8 drm_dp_calc_sb_hdr_size(struct 
> drm_dp_sideband_msg_hdr *hdr)
> +{
> + u8 size = 3;
> + size += (hdr->lct / 2);
> + return size;
> +}
> +
> +static void drm_dp_encode_sideband_msg_hdr(struct 
> drm_dp_sideband_msg_hdr *hdr,
> + u8 *buf, int *len)
> +{
> + int idx = 0;
> + int i;
> + u8 crc4;
> + buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
> + for (i = 0; i < (hdr->lct / 2); i++)
> + buf[idx++] = hdr->rad[i];
> + buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
> + (hdr->msg_len & 0x3f);
> + buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
> +
> + crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
> + buf[idx - 1] |= (crc4 & 0xf);
> +
> + *len = idx;
> +}
> +
> +static bool drm_dp_decode_sideband_msg_hdr(struct 
> drm_dp_sideband_msg_hdr *hdr,
> + u8 *buf, int buflen, u8 *hdrlen)
> +{
> + u8 crc4;
> + u8 len;
> + int i;
> + u8 idx;
> + if (buf[0] == 0)
> + return false;
> + len = 3;
> + len += ((buf[0] & 0xf0) >> 4) / 2;
> + if (len > buflen)
> + return false;
> + crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
> +
> + if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
> + DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
> + return false;
> + }
> +
> + hdr->lct = (buf[0] & 0xf0) >> 4;
> + hdr->lcr = (buf[0] & 0xf);
> + idx = 1;
> + for (i = 0; i < (hdr->lct / 2); i++)
> + hdr->rad[i] = buf[idx++];
> + hdr->broadcast = (buf[idx] >> 7) & 0x1;
> + hdr->path_msg = (buf[idx] >> 6) & 0x1;
> + hdr->msg_len = buf[idx] & 0x3f;
> + idx++;
> + hdr->somt = (buf[idx] >> 7) & 0x1;
> + hdr->eomt = (buf[idx] >> 6) & 0x1;
> + hdr->seqno = (buf[idx] >> 4) & 0x1;
> + idx++;
> + *hdrlen = idx;
> + return true;
> +}
> +
> +static void drm_dp_encode_sideband_req(struct 
> drm_dp_sideband_msg_req_body *req,
> + struct drm_dp_sideband_msg_tx *raw)
> +{
> + int idx = 0;
> + int i;
> + u8 *buf = raw->msg;
> + buf[idx++] = req->req_type & 0x7f;
> +
> + switch (req->req_type) {
> + case DP_ENUM_PATH_RESOURCES:
> + buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
> + idx++;
> + break;
> + case DP_ALLOCATE_PAYLOAD:
> + buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
> + (req->u.allocate_payload.number_sdp_streams & 0xf);
> + idx++;
> + buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
> + idx++;
> + buf[idx] = (req->u.allocate_payload.pbn >> 8);
> + idx++;
> + buf[idx] = (req->u.allocate_payload.pbn & 0xff);
> + idx++;
> + for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
> + buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) 
> << 4) |
> + (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
> + idx++;
> + }
> + if (req->u.allocate_payload.number_sdp_streams & 1) {
> + i = req->u.allocate_payload.number_sdp_streams - 1;
> + buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
> + idx++;
> + }
> + break;
> + case DP_QUERY_PAYLOAD:
> + buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
> + idx++;
> + buf[idx] = (req->u.query_payload.vcpi & 0x7f);
> + idx++;
> + break;
> + case DP_REMOTE_DPCD_READ:
> + buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
> + buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
> + idx++;
> + buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
> + idx++;
> + buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
> + idx++;
> + buf[idx] = (req->u.dpcd_read.num_bytes);
> + idx++;
> + break;
> +
> + case DP_REMOTE_DPCD_WRITE:
> + buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
> + buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
> + idx++;
> + buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
> + idx++;
> + buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
> + idx++;
> + buf[idx] = (req->u.dpcd_write.num_bytes);
> + idx++;
> + memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
> + idx += req->u.dpcd_write.num_bytes;
> + break;
> + case DP_REMOTE_I2C_READ:
> + buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
> + buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
> + idx++;
> + for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
> + buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
>
> + idx++;
> + buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
> + idx++;
> + memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, 
> req->u.i2c_read.transactions[i].num_bytes);
> + idx += req->u.i2c_read.transactions[i].num_bytes;
> +
> + buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
> + buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 
> 0xf);
> + idx++;
> + }
> + buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
> + idx++;
> + buf[idx] = (req->u.i2c_read.num_bytes_read);
> + idx++;
> + break;
> +
> + case DP_REMOTE_I2C_WRITE:
> + buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
> + idx++;
> + buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
> + idx++;
> + buf[idx] = (req->u.i2c_write.num_bytes);
> + idx++;
> + memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
> + idx += req->u.i2c_write.num_bytes;
> + break;
> + }
> + raw->cur_len = idx;
> +}
> +
> +static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
> +{
> + u8 crc4;
> + crc4 = drm_dp_msg_data_crc4(msg, len);
> + msg[len] = crc4;
> +}
> +
> +static void drm_dp_encode_sideband_reply(struct 
> drm_dp_sideband_msg_reply_body *rep,
> + struct drm_dp_sideband_msg_tx *raw)
> +{
> + int idx = 0;
> + u8 *buf = raw->msg;
> +
> + buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
> +
> + raw->cur_len = idx;
> +}
> +
> +/* this adds a chunk of msg to the builder to get the final msg */
> +static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
> + u8 *replybuf, u8 replybuflen, bool hdr)
> +{
> + int ret;
> + u8 crc4;
> +
> + if (hdr) {
> + u8 hdrlen;
> + struct drm_dp_sideband_msg_hdr recv_hdr;
> + ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, 
> replybuflen, &hdrlen);
> + if (ret == false) {
> + print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, 
> replybuf, replybuflen, false);
> + return false;
> + }
> +
> + /* get length contained in this portion */
> + msg->curchunk_len = recv_hdr.msg_len;
> + msg->curchunk_hdrlen = hdrlen;
> +
> + /* we have already gotten an somt - don't bother parsing */
> + if (recv_hdr.somt && msg->have_somt)
> + return false;
> +
> + if (recv_hdr.somt) {
> + memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct 
> drm_dp_sideband_msg_hdr));
> + msg->have_somt = true;
> + }
> + if (recv_hdr.eomt)
> + msg->have_eomt = true;
> +
> + /* copy the bytes for the remainder of this header chunk */
> + msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
> + memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
> + } else {
> + memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
> + msg->curchunk_idx += replybuflen;
> + }
> +
> + if (msg->curchunk_idx >= msg->curchunk_len) {
> + /* do CRC */
> + crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
> + /* copy chunk into bigger msg */
> + memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
> + msg->curlen += msg->curchunk_len - 1;
> + }
> + return true;
> +}
> +
> +static bool drm_dp_sideband_parse_link_address(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + int i;
> + memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
> + idx += 16;
> + repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + for (i = 0; i < repmsg->u.link_addr.nports; i++) {
> + if (raw->msg[idx] & 0x80)
> + repmsg->u.link_addr.ports[i].input_port = 1;
> +
> + repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) 
> & 0x7;
> + repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
> +
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
> + repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
> + if (repmsg->u.link_addr.ports[i].input_port == 0)
> + repmsg->u.link_addr.ports[i].legacy_device_plug_status = 
> (raw->msg[idx] >> 5) & 0x1;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + if (repmsg->u.link_addr.ports[i].input_port == 0) {
> + repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
> + idx += 16;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) 
> & 0xf;
> + repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 
> 0xf);
> + idx++;
> +
> + }
> + if (idx > raw->curlen)
> + goto fail_len;
> + }
> +
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_remote_dpcd_read(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
> + if (idx > raw->curlen)
> + goto fail_len;
> +
> + memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], 
> repmsg->u.remote_dpcd_read_ack.num_bytes);
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_remote_dpcd_write(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> +
> + repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
> + idx++;
> + /* TODO check */
> + memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], 
> repmsg->u.remote_i2c_read_ack.num_bytes);
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_enum_path_resources_ack(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 
> 8) | (raw->msg[idx+1]);
> + idx += 2;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 
> 8) | (raw->msg[idx+1]);
> + idx += 2;
> + if (idx > raw->curlen)
> + goto fail_len;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_allocate_payload_ack(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.allocate_payload.vcpi = raw->msg[idx];
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | 
> (raw->msg[idx+1]);
> + idx += 2;
> + if (idx > raw->curlen)
> + goto fail_len;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_query_payload_ack(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_reply_body *repmsg)
> +{
> + int idx = 1;
> + repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> + repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | 
> (raw->msg[idx + 1]);
> + idx += 2;
> + if (idx > raw->curlen)
> + goto fail_len;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, 
> raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx 
> *raw,
> + struct drm_dp_sideband_msg_reply_body *msg)
> +{
> + memset(msg, 0, sizeof(*msg));
> + msg->reply_type = (raw->msg[0] & 0x80) >> 7;
> + msg->req_type = (raw->msg[0] & 0x7f);
> +
> + if (msg->reply_type) {
> + memcpy(msg->u.nak.guid, &raw->msg[1], 16);
> + msg->u.nak.reason = raw->msg[17];
> + msg->u.nak.nak_data = raw->msg[18];
> + return false;
> + }
> +
> + switch (msg->req_type) {
> + case DP_LINK_ADDRESS:
> + return drm_dp_sideband_parse_link_address(raw, msg);
> + case DP_QUERY_PAYLOAD:
> + return drm_dp_sideband_parse_query_payload_ack(raw, msg);
> + case DP_REMOTE_DPCD_READ:
> + return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
> + case DP_REMOTE_DPCD_WRITE:
> + return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
> + case DP_REMOTE_I2C_READ:
> + return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
> + case DP_ENUM_PATH_RESOURCES:
> + return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
> + case DP_ALLOCATE_PAYLOAD:
> + return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
> + default:
> + DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
> + return false;
> + }
> +}
> +
> +static bool drm_dp_sideband_parse_connection_status_notify(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_req_body *msg)
> +{
> + int idx = 1;
> +
> + msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> +
> + memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
> + idx += 16;
> + if (idx > raw->curlen)
> + goto fail_len;
> +
> + msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
> + msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 
> 5) & 0x1;
> + msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
> + msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
> + msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
> + idx++;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", 
> idx, raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_resource_status_notify(struct 
> drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_req_body *msg)
> +{
> + int idx = 1;
> +
> + msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
> + idx++;
> + if (idx > raw->curlen)
> + goto fail_len;
> +
> + memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
> + idx += 16;
> + if (idx > raw->curlen)
> + goto fail_len;
> +
> + msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | 
> (raw->msg[idx + 1]);
> + idx++;
> + return true;
> +fail_len:
> + DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", 
> idx, raw->curlen);
> + return false;
> +}
> +
> +static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
> + struct drm_dp_sideband_msg_req_body *msg)
> +{
> + memset(msg, 0, sizeof(*msg));
> + msg->req_type = (raw->msg[0] & 0x7f);
> +
> + switch (msg->req_type) {
> + case DP_CONNECTION_STATUS_NOTIFY:
> + return drm_dp_sideband_parse_connection_status_notify(raw, msg);
> + case DP_RESOURCE_STATUS_NOTIFY:
> + return drm_dp_sideband_parse_resource_status_notify(raw, msg);
> + default:
> + DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
> + return false;
> + }
> +}
> +
> +static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 
> port_num, u32 offset, u8 num_bytes, u8 *bytes)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> +
> + req.req_type = DP_REMOTE_DPCD_WRITE;
> + req.u.dpcd_write.port_number = port_num;
> + req.u.dpcd_write.dpcd_address = offset;
> + req.u.dpcd_write.num_bytes = num_bytes;
> + memcpy(req.u.dpcd_write.bytes, bytes, num_bytes);
> + drm_dp_encode_sideband_req(&req, msg);
> +
> + return 0;
> +}
> +
> +static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> +
> + req.req_type = DP_LINK_ADDRESS;
> + drm_dp_encode_sideband_req(&req, msg);
> + return 0;
> +}
> +
> +static int build_enum_path_resources(struct drm_dp_sideband_msg_tx 
> *msg, int port_num)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> +
> + req.req_type = DP_ENUM_PATH_RESOURCES;
> + req.u.port_num.port_number = port_num;
> + drm_dp_encode_sideband_req(&req, msg);
>
> + msg->path_msg = true;
> + return 0;
> +}
> +
> +static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, 
> int port_num,
> + u8 vcpi, uint16_t pbn)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> + memset(&req, 0, sizeof(req));
> + req.req_type = DP_ALLOCATE_PAYLOAD;
> + req.u.allocate_payload.port_number = port_num;
> + req.u.allocate_payload.vcpi = vcpi;
> + req.u.allocate_payload.pbn = pbn;
> + drm_dp_encode_sideband_req(&req, msg);
> + msg->path_msg = true;
> + return 0;
> +}
> +
> +static int drm_dp_mst_assign_payload_id(struct 
> drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_vcpi *vcpi)
> +{
> + int ret;
> +
> + mutex_lock(&mgr->payload_lock);
> + ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
> + if (ret > mgr->max_payloads) {
> + ret = -EINVAL;
> + DRM_DEBUG_KMS("out of payload ids %d\n", ret);
> + goto out_unlock;
> + }
> +
> + set_bit(ret, &mgr->payload_mask);
> + vcpi->vcpi = ret;
> + mgr->proposed_vcpis[ret - 1] = vcpi;
> +out_unlock:
> + mutex_unlock(&mgr->payload_lock);
> + return ret;
> +}
> +
> +static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr 
> *mgr,
> + int id)
> +{
> + if (id == 0)
> + return;
> +
> + mutex_lock(&mgr->payload_lock);
> + DRM_DEBUG_KMS("putting payload %d\n", id);
> + clear_bit(id, &mgr->payload_mask);
> + mgr->proposed_vcpis[id - 1] = NULL;
> + mutex_unlock(&mgr->payload_lock);
> +}
> +
> +static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_sideband_msg_tx *txmsg)
> +{
> + bool ret;
> + mutex_lock(&mgr->qlock);
> + ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
> + txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
> + mutex_unlock(&mgr->qlock);
> + return ret;
> +}
> +
> +static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
> + struct drm_dp_sideband_msg_tx *txmsg)
> +{
> + struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
> + int ret;
> +
> + ret = wait_event_timeout(mgr->tx_waitq,
> + check_txmsg_state(mgr, txmsg),
> + (4 * HZ));
> + mutex_lock(&mstb->mgr->qlock);
> + if (ret > 0) {
> + if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
> + ret = -EIO;
> + goto out;
> + }
> + } else {
> + DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, 
> txmsg->seqno);
> +
> + /* dump some state */
> + ret = -EIO;
> +
> + /* remove from q */
> + if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
> + txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
> + list_del(&txmsg->next);
> + }
> +
> + if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
> + txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
> + mstb->tx_slots[txmsg->seqno] = NULL;
> + }
> + }
> +out:
> + mutex_unlock(&mgr->qlock);
> +
> + return ret;
> +}
> +
> +static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, 
> u8 *rad)
> +{
> + struct drm_dp_mst_branch *mstb;
> +
> + mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
> + if (!mstb)
> + return NULL;
> +
> + mstb->lct = lct;
> + if (lct > 1)
> + memcpy(mstb->rad, rad, lct / 2);
> + INIT_LIST_HEAD(&mstb->ports);
> + kref_init(&mstb->kref);
> + return mstb;
> +}
> +
> +static void drm_dp_destroy_mst_branch_device(struct kref *kref)
> +{
> + struct drm_dp_mst_branch *mstb = container_of(kref, struct 
> drm_dp_mst_branch, kref);
> + struct drm_dp_mst_port *port, *tmp;
> + bool wake_tx = false;
> +
> + cancel_work_sync(&mstb->mgr->work);
> +
> + /*
> + * destroy all ports - don't need lock
> + * as there are no more references to the mst branch
> + * device at this point.
> + */
> + list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
> + list_del(&port->next);
> + drm_dp_put_port(port);
> + }
> +
> + /* drop any tx slots msg */
> + mutex_lock(&mstb->mgr->qlock);
> + if (mstb->tx_slots[0]) {
> + mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
> + mstb->tx_slots[0] = NULL;
> + wake_tx = true;
> + }
> + if (mstb->tx_slots[1]) {
> + mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
> + mstb->tx_slots[1] = NULL;
> + wake_tx = true;
> + }
> + mutex_unlock(&mstb->mgr->qlock);
> +
> + if (wake_tx)
> + wake_up(&mstb->mgr->tx_waitq);
> + kfree(mstb);
> +}
> +
> +static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
> +{
> + kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
> +}
> +
> +
> +static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, 
> int old_pdt)
> +{
> + switch (old_pdt) {
> + case DP_PEER_DEVICE_DP_LEGACY_CONV:
> + case DP_PEER_DEVICE_SST_SINK:
> + /* remove i2c over sideband */
> + drm_dp_mst_unregister_i2c_bus(&port->aux);
> + break;
> + case DP_PEER_DEVICE_MST_BRANCHING:
> + drm_dp_put_mst_branch_device(port->mstb);
> + port->mstb = NULL;
> + break;
> + }
> +}
> +
> +static void drm_dp_destroy_port(struct kref *kref)
> +{
> + struct drm_dp_mst_port *port = container_of(kref, struct 
> drm_dp_mst_port, kref);
> + struct drm_dp_mst_topology_mgr *mgr = port->mgr;
> + if (!port->input) {
> + port->vcpi.num_slots = 0;
> + if (port->connector)
> + (*port->mgr->cbs->destroy_connector)(mgr, port->connector);
> + drm_dp_port_teardown_pdt(port, port->pdt);
> +
> + if (!port->input && port->vcpi.vcpi > 0)
> + drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
> + }
> + kfree(port);
> +}
> +
> +static void drm_dp_put_port(struct drm_dp_mst_port *port)
> +{
> + kref_put(&port->kref, drm_dp_destroy_port);
> +}
> +
> +static struct drm_dp_mst_branch 
> *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch 
> *mstb, struct drm_dp_mst_branch *to_find)
> +{
> + struct drm_dp_mst_port *port;
> + struct drm_dp_mst_branch *rmstb;
> + if (to_find == mstb) {
> + kref_get(&mstb->kref);
> + return mstb;
> + }
> + list_for_each_entry(port, &mstb->ports, next) {
> + if (port->mstb) {
> + rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
> + if (rmstb)
> + return rmstb;
> + }
> + }
> + return NULL;
> +}
> +
> +static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct 
> drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
> +{
> + struct drm_dp_mst_branch *rmstb = NULL;
> + mutex_lock(&mgr->lock);
> + if (mgr->mst_primary)
> + rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, 
> mstb);
> + mutex_unlock(&mgr->lock);
> + return rmstb;
> +}
> +
> +static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct 
> drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
> +{
> + struct drm_dp_mst_port *port, *mport;
> +
> + list_for_each_entry(port, &mstb->ports, next) {
> + if (port == to_find) {
> + kref_get(&port->kref);
> + return port;
> + }
> + if (port->mstb) {
> + mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
> + if (mport)
> + return mport;
> + }
> + }
> + return NULL;
> +}
> +
> +static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct 
> drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
> +{
> + struct drm_dp_mst_port *rport = NULL;
> + mutex_lock(&mgr->lock);
> + if (mgr->mst_primary)
> + rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
> + mutex_unlock(&mgr->lock);
> + return rport;
> +}
> +
> +static struct drm_dp_mst_port *drm_dp_get_port(struct 
> drm_dp_mst_branch *mstb, u8 port_num)
> +{
> + struct drm_dp_mst_port *port;
> +
> + list_for_each_entry(port, &mstb->ports, next) {
> + if (port->port_num == port_num) {
> + kref_get(&port->kref);
> + return port;
> + }
> + }
> +
> + return NULL;
> +}
> +
> +/*
> + * calculate a new RAD for this MST branch device
> + * if parent has an LCT of 2 then it has 1 nibble of RAD,
> + * if parent has an LCT of 3 then it has 2 nibbles of RAD,
> + */
> +static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
> + u8 *rad)
> +{
> + int lct = port->parent->lct;
> + int shift = 4;
> + int idx = lct / 2;
> + if (lct > 1) {
> + memcpy(rad, port->parent->rad, idx);
> + shift = (lct % 2) ? 4 : 0;
> + } else
> + rad[0] = 0;
> +
> + rad[idx] |= port->port_num << shift;
> + return lct + 1;
> +}
> +
> +/*
> + * return sends link address for new mstb
> + */
> +static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
> +{
> + int ret;
> + u8 rad[6], lct;
> + bool send_link = false;
> + switch (port->pdt) {
> + case DP_PEER_DEVICE_DP_LEGACY_CONV:
> + case DP_PEER_DEVICE_SST_SINK:
> + /* add i2c over sideband */
> + ret = drm_dp_mst_register_i2c_bus(&port->aux);
> + break;
> + case DP_PEER_DEVICE_MST_BRANCHING:
> + lct = drm_dp_calculate_rad(port, rad);
> +
> + port->mstb = drm_dp_add_mst_branch_device(lct, rad);
> + port->mstb->mgr = port->mgr;
> + port->mstb->port_parent = port;
> +
> + send_link = true;
> + break;
> + }
> + return send_link;
> +}
> +
> +static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
> + struct drm_dp_mst_port *port)
> +{
> + int ret;
> + if (port->dpcd_rev >= 0x12) {
> + port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
> + if (!port->guid_valid) {
> + ret = drm_dp_send_dpcd_write(mstb->mgr,
> + port,
> + DP_GUID,
> + 16, port->guid);
> + port->guid_valid = true;
> + }
> + }
> +}
> +
> +static void build_mst_prop_path(struct drm_dp_mst_port *port,
> + struct drm_dp_mst_branch *mstb,
> + char *proppath)
> +{
> + int i;
> + char temp[8];
> + snprintf(proppath, 255, "mst:%d", mstb->mgr->conn_base_id);
> + for (i = 0; i < (mstb->lct - 1); i++) {
> + int shift = (i % 2) ? 0 : 4;
> + int port_num = mstb->rad[i / 2] >> shift;
> + snprintf(temp, 8, "-%d", port_num);
> + strncat(proppath, temp, 255);
> + }
> + snprintf(temp, 8, "-%d", port->port_num);
> + strncat(proppath, temp, 255);
> +}
> +
> +static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
> + struct device *dev,
> + struct drm_dp_link_addr_reply_port *port_msg)
> +{
> + struct drm_dp_mst_port *port;
> + bool ret;
> + bool created = false;
> + int old_pdt = 0;
> + int old_ddps = 0;
> + port = drm_dp_get_port(mstb, port_msg->port_number);
> + if (!port) {
> + port = kzalloc(sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return;
> + kref_init(&port->kref);
> + port->parent = mstb;
> + port->port_num = port_msg->port_number;
> + port->mgr = mstb->mgr;
> + port->aux.name = "DPMST";
> + port->aux.dev = dev;
> + created = true;
> + } else {
> + old_pdt = port->pdt;
> + old_ddps = port->ddps;
> + }
> +
> + port->pdt = port_msg->peer_device_type;
> + port->input = port_msg->input_port;
> + port->mcs = port_msg->mcs;
> + port->ddps = port_msg->ddps;
> + port->ldps = port_msg->legacy_device_plug_status;
> + port->dpcd_rev = port_msg->dpcd_revision;
> +
> + memcpy(port->guid, port_msg->peer_guid, 16);
> +
> + /* manage mstb port lists with mgr lock - take a reference
> + for this list */
> + if (created) {
> + mutex_lock(&mstb->mgr->lock);
> + kref_get(&port->kref);
> + list_add(&port->next, &mstb->ports);
> + mutex_unlock(&mstb->mgr->lock);
> + }
> +
> + if (old_ddps != port->ddps) {
> + if (port->ddps) {
> + drm_dp_check_port_guid(mstb, port);
> + if (!port->input)
> + drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
> + } else {
> + port->guid_valid = false;
> + port->available_pbn = 0;
> + }
> + }
> +
> + if (old_pdt != port->pdt && !port->input) {
> + drm_dp_port_teardown_pdt(port, old_pdt);
> +
> + ret = drm_dp_port_setup_pdt(port);
> + if (ret == true) {
> + drm_dp_send_link_address(mstb->mgr, port->mstb);
> + port->mstb->link_address_sent = true;
> + }
> + }
> +
> + if (created && !port->input) {
> + char proppath[255];
> + build_mst_prop_path(port, mstb, proppath);
> + port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, 
> proppath);
> + }
> +
> + /* put reference to this port */
> + drm_dp_put_port(port);
> +}
> +
> +static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
> + struct drm_dp_connection_status_notify *conn_stat)
> +{
> + struct drm_dp_mst_port *port;
> + int old_pdt;
> + int old_ddps;
> + bool dowork = false;
> + port = drm_dp_get_port(mstb, conn_stat->port_number);
> + if (!port)
> + return;
> +
> + old_ddps = port->ddps;
> + old_pdt = port->pdt;
> + port->pdt = conn_stat->peer_device_type;
> + port->mcs = conn_stat->message_capability_status;
> + port->ldps = conn_stat->legacy_device_plug_status;
> + port->ddps = conn_stat->displayport_device_plug_status;
> +
> + if (old_ddps != port->ddps) {
> + if (port->ddps) {
> + drm_dp_check_port_guid(mstb, port);
> + dowork = true;
> + } else {
> + port->guid_valid = false;
> + port->available_pbn = 0;
> + }
> + }
> + if (old_pdt != port->pdt && !port->input) {
> + drm_dp_port_teardown_pdt(port, old_pdt);
> +
> + if (drm_dp_port_setup_pdt(port))
> + dowork = true;
> + }
> +
> + drm_dp_put_port(port);
> + if (dowork)
> + queue_work(system_long_wq, &mstb->mgr->work);
> +
> +}
> +
> +static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct 
> drm_dp_mst_topology_mgr *mgr,
> + u8 lct, u8 *rad)
> +{
> + struct drm_dp_mst_branch *mstb;
> + struct drm_dp_mst_port *port;
> + int i;
> + /* find the port by iterating down */
> + mstb = mgr->mst_primary;
> +
> + for (i = 0; i < lct - 1; i++) {
> + int shift = (i % 2) ? 0 : 4;
> + int port_num = rad[i / 2] >> shift;
> +
> + list_for_each_entry(port, &mstb->ports, next) {
> + if (port->port_num == port_num) {
> + if (!port->mstb) {
> + DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
> + return NULL;
> + }
> +
> + mstb = port->mstb;
> + break;
> + }
> + }
> + }
> + kref_get(&mstb->kref);
> + return mstb;
> +}
> +
> +static void drm_dp_check_and_send_link_address(struct 
> drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb)
> +{
> + struct drm_dp_mst_port *port;
> +
> + if (!mstb->link_address_sent) {
> + drm_dp_send_link_address(mgr, mstb);
> + mstb->link_address_sent = true;
> + }
> + list_for_each_entry(port, &mstb->ports, next) {
> + if (port->input)
> + continue;
> +
> + if (!port->ddps)
> + continue;
> +
> + if (!port->available_pbn)
> + drm_dp_send_enum_path_resources(mgr, mstb, port);
> +
> + if (port->mstb)
> + drm_dp_check_and_send_link_address(mgr, port->mstb);
> + }
> +}
> +
> +static void drm_dp_mst_link_probe_work(struct work_struct *work)
> +{
> + struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct 
> drm_dp_mst_topology_mgr, work);
> +
> + drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
> +
> +}
> +
> +static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
> + u8 *guid)
> +{
> + static u8 zero_guid[16];
> +
> + if (!memcmp(guid, zero_guid, 16)) {
> + u64 salt = get_jiffies_64();
> + memcpy(&guid[0], &salt, sizeof(u64));
> + memcpy(&guid[8], &salt, sizeof(u64));
> + return false;
> + }
> + return true;
> +}
> +
> +#if 0
> +static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 
> port_num, u32 offset, u8 num_bytes)
> +{
> + struct drm_dp_sideband_msg_req_body req;
> +
> + req.req_type = DP_REMOTE_DPCD_READ;
> + req.u.dpcd_read.port_number = port_num;
> + req.u.dpcd_read.dpcd_address = offset;
> + req.u.dpcd_read.num_bytes = num_bytes;
> + drm_dp_encode_sideband_req(&req, msg);
> +
> + return 0;
> +}
> +#endif
> +
> +static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
> + bool up, u8 *msg, int len)
> +{
> + int ret;
> + int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : 
> DP_SIDEBAND_MSG_DOWN_REQ_BASE;
> + int tosend, total, offset;
> + int retries = 0;
> +
> +retry:
> + total = len;
> + offset = 0;
> + do {
> + tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
> +
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
> + &msg[offset],
> + tosend);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != tosend) {
> + if (ret == -EIO && retries < 5) {
> + retries++;
> + goto retry;
> + }
> + DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
> + WARN(1, "fail\n");
> +
> + return -EIO;
> + }
> + offset += tosend;
> + total -= tosend;
> + } while (total > 0);
> + return 0;
> +}
> +
> +static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
> + struct drm_dp_sideband_msg_tx *txmsg)
> +{
> + struct drm_dp_mst_branch *mstb = txmsg->dst;
> +
> + /* both msg slots are full */
> + if (txmsg->seqno == -1) {
> + if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
> + DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
> + return -EAGAIN;
> + }
> + if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
> + txmsg->seqno = mstb->last_seqno;
> + mstb->last_seqno ^= 1;
> + } else if (mstb->tx_slots[0] == NULL)
> + txmsg->seqno = 0;
> + else
> + txmsg->seqno = 1;
> + mstb->tx_slots[txmsg->seqno] = txmsg;
> + }
> + hdr->broadcast = 0;
> + hdr->path_msg = txmsg->path_msg;
> + hdr->lct = mstb->lct;
> + hdr->lcr = mstb->lct - 1;
> + if (mstb->lct > 1)
> + memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
> + hdr->seqno = txmsg->seqno;
> + return 0;
> +}
> +/*
> + * process a single block of the next message in the sideband queue
> + */
> +static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_sideband_msg_tx *txmsg,
> + bool up)
> +{
> + u8 chunk[48];
> + struct drm_dp_sideband_msg_hdr hdr;
> + int len, space, idx, tosend;
> + int ret;
> +
> + if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
> + txmsg->seqno = -1;
> + txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
> + }
> +
> + /* make hdr from dst mst - for replies use seqno
> + otherwise assign one */
> + ret = set_hdr_from_dst_qlock(&hdr, txmsg);
> + if (ret < 0)
> + return ret;
> +
> + /* amount left to send in this message */
> + len = txmsg->cur_len - txmsg->cur_offset;
> +
> + /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
> + space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
> +
> + tosend = min(len, space);
> + if (len == txmsg->cur_len)
> + hdr.somt = 1;
> + if (space >= len)
> + hdr.eomt = 1;
> +
> +
> + hdr.msg_len = tosend + 1;
> + drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
> + memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
> + /* add crc at end */
> + drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
> + idx += tosend + 1;
> +
> + ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
> + if (ret) {
> + DRM_DEBUG_KMS("sideband msg failed to send\n");
> + return ret;
> + }
> +
> + txmsg->cur_offset += tosend;
> + if (txmsg->cur_offset == txmsg->cur_len) {
> + txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
> + return 1;
> + }
> + return 0;
> +}
> +
> +/* must be called holding qlock */
> +static void process_single_down_tx_qlock(struct 
> drm_dp_mst_topology_mgr *mgr)
> +{
> + struct drm_dp_sideband_msg_tx *txmsg;
> + int ret;
> +
> + /* construct a chunk from the first msg in the tx_msg queue */
> + if (list_empty(&mgr->tx_msg_downq)) {
> + mgr->tx_down_in_progress = false;
> + return;
> + }
> + mgr->tx_down_in_progress = true;
> +
> + txmsg = list_first_entry(&mgr->tx_msg_downq, struct 
> drm_dp_sideband_msg_tx, next);
> + ret = process_single_tx_qlock(mgr, txmsg, false);
> + if (ret == 1) {
> + /* txmsg is sent it should be in the slots now */
> + list_del(&txmsg->next);
> + } else if (ret) {
> + DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
> + list_del(&txmsg->next);
> + if (txmsg->seqno != -1)
> + txmsg->dst->tx_slots[txmsg->seqno] = NULL;
> + txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
> + wake_up(&mgr->tx_waitq);
> + }
> + if (list_empty(&mgr->tx_msg_downq)) {
> + mgr->tx_down_in_progress = false;
> + return;
> + }
> +}
> +
> +/* called holding qlock */
> +static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr 
> *mgr)
> +{
> + struct drm_dp_sideband_msg_tx *txmsg;
> + int ret;
> +
> + /* construct a chunk from the first msg in the tx_msg queue */
> + if (list_empty(&mgr->tx_msg_upq)) {
> + mgr->tx_up_in_progress = false;
> + return;
> + }
> +
> + txmsg = list_first_entry(&mgr->tx_msg_upq, struct 
> drm_dp_sideband_msg_tx, next);
> + ret = process_single_tx_qlock(mgr, txmsg, true);
> + if (ret == 1) {
> + /* up txmsgs aren't put in slots - so free after we send it */
> + list_del(&txmsg->next);
> + kfree(txmsg);
> + } else if (ret)
> + DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
> + mgr->tx_up_in_progress = true;
> +}
> +
> +static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_sideband_msg_tx *txmsg)
> +{
> + mutex_lock(&mgr->qlock);
> + list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
> + if (!mgr->tx_down_in_progress)
> + process_single_down_tx_qlock(mgr);
> + mutex_unlock(&mgr->qlock);
> +}
> +
> +static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb)
> +{
> + int len;
> + struct drm_dp_sideband_msg_tx *txmsg;
> + int ret;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg)
> + return -ENOMEM;
> +
> + txmsg->dst = mstb;
> + len = build_link_address(txmsg);
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
> + if (ret > 0) {
> + int i;
> +
> + if (txmsg->reply.reply_type == 1)
> + DRM_DEBUG_KMS("link address nak received\n");
> + else {
> + DRM_DEBUG_KMS("link address reply: %d\n", 
> txmsg->reply.u.link_addr.nports);
> + for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
> + DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, 
> mcs: %d, ddps: %d, ldps %d\n", i,
> + txmsg->reply.u.link_addr.ports[i].input_port,
> + txmsg->reply.u.link_addr.ports[i].peer_device_type,
> + txmsg->reply.u.link_addr.ports[i].port_number,
> + txmsg->reply.u.link_addr.ports[i].dpcd_revision,
> + txmsg->reply.u.link_addr.ports[i].mcs,
> + txmsg->reply.u.link_addr.ports[i].ddps,
> + txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status);
> + }
> + for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
> + drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
> + }
> + (*mgr->cbs->hotplug)(mgr);
> + }
> + } else
> + DRM_DEBUG_KMS("link address failed %d\n", ret);
> +
> + kfree(txmsg);
> + return 0;
> +}
> +
> +static int drm_dp_send_enum_path_resources(struct 
> drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb,
> + struct drm_dp_mst_port *port)
> +{
> + int len;
> + struct drm_dp_sideband_msg_tx *txmsg;
> + int ret;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg)
> + return -ENOMEM;
> +
> + txmsg->dst = mstb;
> + len = build_enum_path_resources(txmsg, port->port_num);
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
> + if (ret > 0) {
> + if (txmsg->reply.reply_type == 1)
> + DRM_DEBUG_KMS("enum path resources nak received\n");
> + else {
> + if (port->port_num != txmsg->reply.u.path_resources.port_number)
> + DRM_ERROR("got incorrect port in response\n");
> + DRM_DEBUG_KMS("enum path resources %d: %d %d\n", 
> txmsg->reply.u.path_resources.port_number, 
> txmsg->reply.u.path_resources.full_payload_bw_number,
> + txmsg->reply.u.path_resources.avail_payload_bw_number);
> + port->available_pbn = 
> txmsg->reply.u.path_resources.avail_payload_bw_number;
> + }
> + }
> +
> + kfree(txmsg);
> + return 0;
> +}
> +
> +int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int id,
> + int pbn)
> +{
> + struct drm_dp_sideband_msg_tx *txmsg;
> + struct drm_dp_mst_branch *mstb;
> + int len, ret;
> +
> + mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
> + if (!mstb)
> + return -EINVAL;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg) {
> + ret = -ENOMEM;
> + goto fail_put;
> + }
> +
> + txmsg->dst = mstb;
> + len = build_allocate_payload(txmsg, port->port_num,
> + id,
> + pbn);
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
> + if (ret > 0) {
> + if (txmsg->reply.reply_type == 1) {
> + ret = -EINVAL;
> + } else
> + ret = 0;
> + }
> + kfree(txmsg);
> +fail_put:
> + drm_dp_put_mst_branch_device(mstb);
> + return ret;
> +}
> +
> +static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr 
> *mgr,
> + int id,
> + struct drm_dp_payload *payload)
> +{
> + int ret;
> +
> + ret = drm_dp_dpcd_write_payload(mgr, id, payload);
> + if (ret < 0) {
> + payload->payload_state = 0;
> + return ret;
> + }
> + payload->payload_state = DP_PAYLOAD_LOCAL;
> + return 0;
> +}
> +
> +int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int id,
> + struct drm_dp_payload *payload)
> +{
> + int ret;
> + ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
> + if (ret < 0)
> + return ret;
> + payload->payload_state = DP_PAYLOAD_REMOTE;
> + return ret;
> +}
> +
> +int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int id,
> + struct drm_dp_payload *payload)
> +{
> + DRM_DEBUG_KMS("\n");
> + /* its okay for these to fail */
> + if (port) {
> + drm_dp_payload_send_msg(mgr, port, id, 0);
> + }
> +
> + drm_dp_dpcd_write_payload(mgr, id, payload);
> + payload->payload_state = 0;
> + return 0;
> +}
> +
> +int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
> + int id,
> + struct drm_dp_payload *payload)
> +{
> + payload->payload_state = 0;
> + return 0;
> +}
> +
> +/**
> + * drm_dp_update_payload_part1() - Execute payload update part 1
> + * @mgr: manager to use.
> + *
> + * This iterates over all proposed virtual channels, and tries to
> + * allocate space in the link for them. For 0->slots transitions,
> + * this step just writes the VCPI to the MST device. For slots->0
> + * transitions, this writes the updated VCPIs and removes the
> + * remote VC payloads.
> + *
> + * after calling this the driver should generate ACT and payload
> + * packets.
> + */
> +int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + int i;
> + int cur_slots = 1;
> + struct drm_dp_payload req_payload;
> + struct drm_dp_mst_port *port;
> +
> + mutex_lock(&mgr->payload_lock);
> + for (i = 0; i < mgr->max_payloads; i++) {
> + /* solve the current payloads - compare to the hw ones
> + - update the hw view */
> + req_payload.start_slot = cur_slots;
> + if (mgr->proposed_vcpis[i]) {
> + port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, 
> vcpi);
> + req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
> + } else {
> + port = NULL;
> + req_payload.num_slots = 0;
> + }
> + /* work out what is required to happen with this payload */
> + if (mgr->payloads[i].start_slot != req_payload.start_slot ||
> + mgr->payloads[i].num_slots != req_payload.num_slots) {
> +
> + /* need to push an update for this payload */
> + if (req_payload.num_slots) {
> + drm_dp_create_payload_step1(mgr, i + 1, &req_payload);
> + mgr->payloads[i].num_slots = req_payload.num_slots;
> + } else if (mgr->payloads[i].num_slots) {
> + mgr->payloads[i].num_slots = 0;
> + drm_dp_destroy_payload_step1(mgr, port, i + 1, &mgr->payloads[i]);
> + req_payload.payload_state = mgr->payloads[i].payload_state;
> + }
> + mgr->payloads[i].start_slot = req_payload.start_slot;
> + mgr->payloads[i].payload_state = req_payload.payload_state;
> + }
> + cur_slots += req_payload.num_slots;
> + }
> + mutex_unlock(&mgr->payload_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_update_payload_part1);
> +
> +/**
> + * drm_dp_update_payload_part2() - Execute payload update part 2
> + * @mgr: manager to use.
> + *
> + * This iterates over all proposed virtual channels, and tries to
> + * allocate space in the link for them. For 0->slots transitions,
> + * this step writes the remote VC payload commands. For slots->0
> + * this just resets some internal state.
> + */
> +int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + struct drm_dp_mst_port *port;
> + int i;
> + int ret;
> + mutex_lock(&mgr->payload_lock);
> + for (i = 0; i < mgr->max_payloads; i++) {
> +
> + if (!mgr->proposed_vcpis[i])
> + continue;
> +
> + port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, 
> vcpi);
> +
> + DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
> + if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
> + ret = drm_dp_create_payload_step2(mgr, port, i + 1, &mgr->payloads[i]);
> + } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
> + ret = drm_dp_destroy_payload_step2(mgr, i + 1, &mgr->payloads[i]);
> + }
> + if (ret) {
> + mutex_unlock(&mgr->payload_lock);
> + return ret;
> + }
> + }
> + mutex_unlock(&mgr->payload_lock);
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_update_payload_part2);
> +
> +#if 0 /* unused as of yet */
> +static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int offset, int size)
> +{
> + int len;
> + struct drm_dp_sideband_msg_tx *txmsg;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg)
> + return -ENOMEM;
> +
> + len = build_dpcd_read(txmsg, port->port_num, 0, 8);
> + txmsg->dst = port->parent;
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + return 0;
> +}
> +#endif
> +
> +static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port,
> + int offset, int size, u8 *bytes)
> +{
> + int len;
> + int ret;
> + struct drm_dp_sideband_msg_tx *txmsg;
> + struct drm_dp_mst_branch *mstb;
> +
> + mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
> + if (!mstb)
> + return -EINVAL;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg) {
> + ret = -ENOMEM;
> + goto fail_put;
> + }
> +
> + len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
> + txmsg->dst = mstb;
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
> + if (ret > 0) {
> + if (txmsg->reply.reply_type == 1) {
> + ret = -EINVAL;
> + } else
> + ret = 0;
> + }
> + kfree(txmsg);
> +fail_put:
> + drm_dp_put_mst_branch_device(mstb);
> + return ret;
> +}
> +
> +static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx 
> *msg, u8 req_type)
> +{
> + struct drm_dp_sideband_msg_reply_body reply;
> +
> + reply.reply_type = 1;
> + reply.req_type = req_type;
> + drm_dp_encode_sideband_reply(&reply, msg);
> + return 0;
> +}
> +
> +static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_branch *mstb,
> + int req_type, int seqno, bool broadcast)
> +{
> + struct drm_dp_sideband_msg_tx *txmsg;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg)
> + return -ENOMEM;
> +
> + txmsg->dst = mstb;
> + txmsg->seqno = seqno;
> + drm_dp_encode_up_ack_reply(txmsg, req_type);
> +
> + mutex_lock(&mgr->qlock);
> + list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
> + if (!mgr->tx_up_in_progress) {
> + process_single_up_tx_qlock(mgr);
> + }
> + mutex_unlock(&mgr->qlock);
> + return 0;
> +}
> +
> +static int drm_dp_get_vc_payload_bw(int dp_link_bw, int dp_link_count)
> +{
> + switch (dp_link_bw) {
> + case DP_LINK_BW_1_62:
> + return 3 * dp_link_count;
> + case DP_LINK_BW_2_7:
> + return 5 * dp_link_count;
> + case DP_LINK_BW_5_4:
> + return 10 * dp_link_count;
> + }
> + return 0;
> +}
> +
> +/**
> + * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a 
> topology manager
> + * @mgr: manager to set state for
> + * @mst_state: true to enable MST on this connector - false to disable.
> + *
> + * This is called by the driver when it detects an MST capable device 
> plugged
> + * into a DP MST capable port, or when a DP MST capable device is 
> unplugged.
> + */
> +int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr 
> *mgr, bool mst_state)
> +{
> + int ret = 0;
> + struct drm_dp_mst_branch *mstb = NULL;
> +
> + mutex_lock(&mgr->lock);
> + if (mst_state == mgr->mst_state)
> + goto out_unlock;
> +
> + mgr->mst_state = mst_state;
> + /* set the device into MST mode */
> + if (mst_state) {
> + WARN_ON(mgr->mst_primary);
> +
> + /* get dpcd info */
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, 
> DP_RECEIVER_CAP_SIZE);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != DP_RECEIVER_CAP_SIZE) {
> + DRM_DEBUG_KMS("failed to read DPCD\n");
> + goto out_unlock;
> + }
> +
> + mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], mgr->dpcd[2] & 
> DP_MAX_LANE_COUNT_MASK);
> + mgr->total_pbn = 2560;
> + mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
> + mgr->avail_slots = mgr->total_slots;
> +
> + /* add initial branch device at LCT 1 */
> + mstb = drm_dp_add_mst_branch_device(1, NULL);
> + if (mstb == NULL) {
> + ret = -ENOMEM;
> + goto out_unlock;
> + }
> + mstb->mgr = mgr;
> +
> + /* give this the main reference */
> + mgr->mst_primary = mstb;
> + kref_get(&mgr->mst_primary->kref);
> +
> + {
> + struct drm_dp_payload reset_pay;
> + reset_pay.start_slot = 0;
> + reset_pay.num_slots = 0x3f;
> + drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
> + }
> +
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> + DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret < 0) {
> + goto out_unlock;
> + }
> +
> +
> + /* sort out guid */
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != 16) {
> + DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
> + goto out_unlock;
> + }
> +
> + mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
> + if (!mgr->guid_valid) {
> + ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
> + mgr->guid_valid = true;
> + }
> +
> + queue_work(system_long_wq, &mgr->work);
> +
> + ret = 0;
> + } else {
> + /* disable MST on the device */
> + mstb = mgr->mst_primary;
> + mgr->mst_primary = NULL;
> + /* this can fail if the device is gone */
> + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
> + ret = 0;
> + memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct 
> drm_dp_payload));
> + mgr->payload_mask = 0;
> + set_bit(0, &mgr->payload_mask);
> + }
> +
> +out_unlock:
> + mutex_unlock(&mgr->lock);
> + if (mstb)
> + drm_dp_put_mst_branch_device(mstb);
> + return ret;
> +
> +}
> +EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
> +
> +/**
> + * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
> + * @mgr: manager to suspend
> + *
> + * This function tells the MST device that we can't handle UP messages
> + * anymore. This should stop it from sending any since we are suspended.
> + */
> +void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + mutex_lock(&mgr->lock);
> + mutex_lock(&mgr->aux_lock);
> + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> + DP_MST_EN | DP_UPSTREAM_IS_SRC);
> + mutex_unlock(&mgr->aux_lock);
> + mutex_unlock(&mgr->lock);
> +}
> +EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
> +
> +/**
> + * drm_dp_mst_topology_mgr_resume() - resume the MST manager
> + * @mgr: manager to resume
> + *
> + * This will fetch DPCD and see if the device is still there,
> + * if it is, it will rewrite the MSTM control bits, and return.
> + *
> + * if the device fails this returns -1, and the driver should do
> + * a full MST reprobe, in case we were undocked.
> + */
> +int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + int ret = 0;
> +
> + mutex_lock(&mgr->lock);
> +
> + if (mgr->mst_primary) {
> + int sret;
> + mutex_lock(&mgr->aux_lock);
> + sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, 
> DP_RECEIVER_CAP_SIZE);
> + mutex_unlock(&mgr->aux_lock);
> + if (sret != DP_RECEIVER_CAP_SIZE) {
> + DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
> + ret = -1;
> + goto out_unlock;
> + }
> +
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
> + DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret < 0) {
> + DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
> + ret = -1;
> + goto out_unlock;
> + }
> + ret = 0;
> + } else
> + ret = -1;
> +
> +out_unlock:
> + mutex_unlock(&mgr->lock);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
> +
> +static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr 
> *mgr, bool up)
> +{
> + int len;
> + u8 replyblock[32];
> + int replylen, origlen, curreply;
> + int ret;
> + struct drm_dp_sideband_msg_rx *msg;
> + int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 
> DP_SIDEBAND_MSG_DOWN_REP_BASE;
> + msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
> +
> + len = min(mgr->max_dpcd_transaction_bytes, 16);
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_read(mgr->aux, basereg,
> + replyblock, len);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != len) {
> + DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
> + return;
> + }
> + ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
> + if (!ret) {
> + DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
> + return;
> + }
> + replylen = msg->curchunk_len + msg->curchunk_hdrlen;
> +
> + origlen = replylen;
> + replylen -= len;
> + curreply = len;
> + while (replylen > 0) {
> + len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
> + replyblock, len);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != len) {
> + DRM_DEBUG_KMS("failed to read a chunk\n");
> + }
> + ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
> + if (ret == false)
> + DRM_DEBUG_KMS("failed to build sideband msg\n");
> + curreply += len;
> + replylen -= len;
> + }
> +}
> +
> +static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr 
> *mgr)
> +{
> + int ret = 0;
> +
> + drm_dp_get_one_sb_msg(mgr, false);
> +
> + if (mgr->down_rep_recv.have_eomt) {
> + struct drm_dp_sideband_msg_tx *txmsg;
> + struct drm_dp_mst_branch *mstb;
> + int slot = -1;
> + mstb = drm_dp_get_mst_branch_device(mgr,
> + mgr->down_rep_recv.initial_hdr.lct,
> + mgr->down_rep_recv.initial_hdr.rad);
> +
> + if (!mstb) {
> + DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", 
> mgr->down_rep_recv.initial_hdr.lct);
> + memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
> + return 0;
> + }
> +
> + /* find the message */
> + slot = mgr->down_rep_recv.initial_hdr.seqno;
> + mutex_lock(&mgr->qlock);
> + txmsg = mstb->tx_slots[slot];
> + /* remove from slots */
> + mutex_unlock(&mgr->qlock);
> +
> + if (!txmsg) {
> + DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
> + mstb,
> + mgr->down_rep_recv.initial_hdr.seqno,
> + mgr->down_rep_recv.initial_hdr.lct,
> + mgr->down_rep_recv.initial_hdr.rad[0],
> + mgr->down_rep_recv.msg[0]);
> + drm_dp_put_mst_branch_device(mstb);
> + memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
> + return 0;
> + }
> +
> + drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
> + if (txmsg->reply.reply_type == 1) {
> + DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 
> 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, 
> txmsg->reply.u.nak.nak_data);
> + }
> +
> + memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
> + drm_dp_put_mst_branch_device(mstb);
> +
> + mutex_lock(&mgr->qlock);
> + txmsg->state = DRM_DP_SIDEBAND_TX_RX;
> + mstb->tx_slots[slot] = NULL;
> + mutex_unlock(&mgr->qlock);
> +
> + wake_up(&mgr->tx_waitq);
> + }
> + return ret;
> +}
> +
> +static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + int ret = 0;
> + drm_dp_get_one_sb_msg(mgr, true);
> +
> + if (mgr->up_req_recv.have_eomt) {
> + struct drm_dp_sideband_msg_req_body msg;
> + struct drm_dp_mst_branch *mstb;
> + bool seqno;
> + mstb = drm_dp_get_mst_branch_device(mgr,
> + mgr->up_req_recv.initial_hdr.lct,
> + mgr->up_req_recv.initial_hdr.rad);
> + if (!mstb) {
> + DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", 
> mgr->up_req_recv.initial_hdr.lct);
> + memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
> + return 0;
> + }
> +
> + seqno = mgr->up_req_recv.initial_hdr.seqno;
> + drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
> +
> + if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
> + drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
> + drm_dp_update_port(mstb, &msg.u.conn_stat);
> + DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: 
> %d\n", msg.u.conn_stat.port_number, 
> msg.u.conn_stat.legacy_device_plug_status, 
> msg.u.conn_stat.displayport_device_plug_status, 
> msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, 
> msg.u.conn_stat.peer_device_type);
> + (*mgr->cbs->hotplug)(mgr);
> +
> + } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
> + drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
> + DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", 
> msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
> + }
> +
> + drm_dp_put_mst_branch_device(mstb);
> + memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
> + }
> + return ret;
> +}
> +
> +/**
> + * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
> + * @mgr: manager to notify irq for.
> + * @esi: 4 bytes from SINK_COUNT_ESI
> + *
> + * This should be called from the driver when it detects a short IRQ,
> + * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
> + * topology manager will process the sideband messages received as a 
> result
> + * of this.
> + */
> +int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, 
> bool *handled)
> +{
> + int ret = 0;
> + int sc;
> + *handled = false;
> + sc = esi[0] & 0x3f;
> + if (sc != mgr->sink_count) {
> +
> + if (mgr->mst_primary && mgr->sink_count == 0 && sc) {
> + mgr->mst_primary->link_address_sent = false;
> + queue_work(system_long_wq, &mgr->work);
> + }
> + mgr->sink_count = sc;
> + *handled = true;
> +
> + }
> +
> + if (esi[1] & DP_DOWN_REP_MSG_RDY) {
> + ret = drm_dp_mst_handle_down_rep(mgr);
> + *handled = true;
> + }
> +
> + if (esi[1] & DP_UP_REQ_MSG_RDY) {
> + ret |= drm_dp_mst_handle_up_req(mgr);
> + *handled = true;
> + }
> +
> + drm_dp_mst_kick_tx(mgr);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
> +
> +/**
> + * drm_dp_mst_detect_port() - get connection status for an MST port
> + * @mgr: manager for this port
> + * @port: unverified pointer to a port
> + *
> + * This returns the current connection state for a port. It validates the
> + * port pointer still exists so the caller doesn't require a reference
> + */
> +enum drm_connector_status drm_dp_mst_detect_port(struct 
> drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
> +{
> + enum drm_connector_status status = connector_status_disconnected;
> +
> + /* we need to search for the port in the mgr in case its gone */
> + port = drm_dp_get_validated_port_ref(mgr, port);
> + if (!port)
> + return connector_status_disconnected;
> +
> + if (!port->ddps)
> + goto out;
> +
> + switch (port->pdt) {
> + case DP_PEER_DEVICE_NONE:
> + case DP_PEER_DEVICE_MST_BRANCHING:
> + break;
> +
> + case DP_PEER_DEVICE_SST_SINK:
> + status = connector_status_connected;
> + break;
> + case DP_PEER_DEVICE_DP_LEGACY_CONV:
> + if (port->ldps)
> + status = connector_status_connected;
> + break;
> + }
> +out:
> + drm_dp_put_port(port);
> + return status;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_detect_port);
> +
> +/**
> + * drm_dp_mst_get_edid() - get EDID for an MST port
> + * @connector: toplevel connector to get EDID for
> + * @mgr: manager for this port
> + * @port: unverified pointer to a port.
> + *
> + * This returns an EDID for the port connected to a connector,
> + * It validates the pointer still exists so the caller doesn't require a
> + * reference.
> + */
> +struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 
> struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
> +{
> + struct edid *edid = NULL;
> +
> + /* we need to search for the port in the mgr in case its gone */
> + port = drm_dp_get_validated_port_ref(mgr, port);
> + if (!port)
> + return NULL;
> +
> + edid = drm_get_edid(connector, &port->aux.ddc);
> + drm_dp_put_port(port);
> + return edid;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_get_edid);
> +
> +/**
> + * drm_dp_find_vcpi_slots() - find slots for this PBN value
> + * @mgr: manager to use
> + * @pbn: payload bandwidth to convert into slots.
> + */
> +int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
> + int pbn)
> +{
> + int num_slots;
> +
> + num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
> +
> + if (num_slots > mgr->avail_slots)
> + return -ENOSPC;
> + return num_slots;
> +}
> +EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
> +
> +static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_vcpi *vcpi, int pbn)
> +{
> + int num_slots;
> + int ret;
> +
> + num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
> +
> + if (num_slots > mgr->avail_slots)
> + return -ENOSPC;
> +
> + vcpi->pbn = pbn;
> + vcpi->aligned_pbn = num_slots * mgr->pbn_div;
> + vcpi->num_slots = num_slots;
> +
> + ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
> + if (ret < 0)
> + return ret;
> + return 0;
> +}
> +
> +/**
> + * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
> + * @mgr: manager for this port
> + * @port: port to allocate a virtual channel for.
> + * @pbn: payload bandwidth number to request
> + * @slots: returned number of slots for this PBN.
> + */
> +bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, 
> struct drm_dp_mst_port *port, int pbn, int *slots)
> +{
> + int ret;
> +
> + port = drm_dp_get_validated_port_ref(mgr, port);
> + if (!port)
> + return false;
> +
> + if (port->vcpi.vcpi > 0) {
> + DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - 
> requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
> + if (pbn == port->vcpi.pbn) {
> + *slots = port->vcpi.num_slots;
> + return true;
> + }
> + }
> +
> + ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
> + if (ret) {
> + DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, 
> mgr->pbn_div), mgr->avail_slots, ret);
> + goto out;
> + }
> + DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
> + *slots = port->vcpi.num_slots;
> +
> + drm_dp_put_port(port);
> + return true;
> +out:
> + return false;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
> +
> +/**
> + * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
> + * @mgr: manager for this port
> + * @port: unverified pointer to a port.
> + *
> + * This just resets the number of slots for the ports VCPI for later 
> programming.
> + */
> +void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, 
> struct drm_dp_mst_port *port)
> +{
> + port = drm_dp_get_validated_port_ref(mgr, port);
> + if (!port)
> + return;
> + port->vcpi.num_slots = 0;
> + drm_dp_put_port(port);
> +}
> +EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
> +
> +/**
> + * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
> + * @mgr: manager for this port
> + * @port: unverified port to deallocate vcpi for
> + */
> +void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, 
> struct drm_dp_mst_port *port)
> +{
> + port = drm_dp_get_validated_port_ref(mgr, port);
> + if (!port)
> + return;
> +
> + drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
> + port->vcpi.num_slots = 0;
> + port->vcpi.pbn = 0;
> + port->vcpi.aligned_pbn = 0;
> + port->vcpi.vcpi = 0;
> + drm_dp_put_port(port);
> +}
> +EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
> +
> +static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
> + int id, struct drm_dp_payload *payload)
> +{
> + u8 payload_alloc[3], status;
> + int ret;
> + int retries = 0;
> +
> + mutex_lock(&mgr->aux_lock);
> + drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
> + DP_PAYLOAD_TABLE_UPDATED);
> + mutex_unlock(&mgr->aux_lock);
> +
> + payload_alloc[0] = id;
> + payload_alloc[1] = payload->start_slot;
> + payload_alloc[2] = payload->num_slots;
> +
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, 
> payload_alloc, 3);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret != 3) {
> + DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
> + goto fail;
> + }
> +
> +retry:
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 
> &status);
> + mutex_unlock(&mgr->aux_lock);
> + if (ret < 0) {
> + DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
> + goto fail;
> + }
> +
> + if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
> + retries++;
> + if (retries < 20) {
> + usleep_range(10000, 20000);
> + goto retry;
> + }
> + DRM_DEBUG_KMS("status not set after read payload table status %d\n", 
> status);
> + ret = -EINVAL;
> + goto fail;
> + }
> + ret = 0;
> +fail:
> + return ret;
> +}
> +
> +
> +/**
> + * drm_dp_check_act_status() - Check ACT handled status.
> + * @mgr: manager to use
> + *
> + * Check the payload status bits in the DPCD for ACT handled completion.
> + */
> +int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + u8 status;
> + int ret;
> + int count = 0;
> +
> + do {
> + mutex_lock(&mgr->aux_lock);
> + ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 
> &status);
> + mutex_unlock(&mgr->aux_lock);
> +
> + if (ret < 0) {
> + DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
> + goto fail;
> + }
> +
> + if (status & DP_PAYLOAD_ACT_HANDLED)
> + break;
> + count++;
> + udelay(100);
> +
> + } while (count < 30);
> +
> + if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
> + DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, 
> count);
> + ret = -EINVAL;
> + goto fail;
> + }
> + return 0;
> +fail:
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_check_act_status);
> +
> +/**
> + * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
> + * @clock: dot clock for the mode
> + * @bpp: bpp for the mode.
> + *
> + * This uses the formula in the spec to calculate the PBN value for a 
> mode.
> + */
> +int drm_dp_calc_pbn_mode(int clock, int bpp)
> +{
> + fixed20_12 pix_bw;
> + fixed20_12 fbpp;
> + fixed20_12 result;
> + fixed20_12 margin, tmp;
> + u32 res;
> +
> + pix_bw.full = dfixed_const(clock);
> + fbpp.full = dfixed_const(bpp);
> + tmp.full = dfixed_const(8);
> + fbpp.full = dfixed_div(fbpp, tmp);
> +
> + result.full = dfixed_mul(pix_bw, fbpp);
> + margin.full = dfixed_const(54);
> + tmp.full = dfixed_const(64);
> + margin.full = dfixed_div(margin, tmp);
> + result.full = dfixed_div(result, margin);
> +
> + margin.full = dfixed_const(1006);
> + tmp.full = dfixed_const(1000);
> + margin.full = dfixed_div(margin, tmp);
> + result.full = dfixed_mul(result, margin);
> +
> + result.full = dfixed_div(result, tmp);
> + result.full = dfixed_ceil(result);
> + res = dfixed_trunc(result);
> + return res;
> +}
> +EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
> +
> +static int test_calc_pbn_mode(void)
> +{
> + int ret;
> + ret = drm_dp_calc_pbn_mode(154000, 30);
> + if (ret != 689)
> + return -EINVAL;
> + ret = drm_dp_calc_pbn_mode(234000, 30);
> + if (ret != 1047)
> + return -EINVAL;
> + return 0;
> +}
> +
> +/* we want to kick the TX after we've ack the up/down IRQs. */
> +static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + queue_work(system_long_wq, &mgr->tx_work);
> +}
> +
> +static void drm_dp_mst_dump_mstb(struct seq_file *m,
> + struct drm_dp_mst_branch *mstb)
> +{
> + struct drm_dp_mst_port *port;
> + int tabs = mstb->lct;
> + char prefix[10];
> + int i;
> +
> + for (i = 0; i < tabs; i++)
> + prefix[i] = '\t';
> + prefix[i] = '\0';
> +
> + seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
> + list_for_each_entry(port, &mstb->ports, next) {
> + seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", 
> prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
> + if (port->mstb)
> + drm_dp_mst_dump_mstb(m, port->mstb);
> + }
> +}
> +
> +static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
> + char *buf)
> +{
> + int ret;
> + int i;
> + mutex_lock(&mgr->aux_lock);
> + for (i = 0; i < 4; i++) {
> + ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i 
> * 16), &buf[i * 16], 16);
> + if (ret != 16)
> + break;
> + }
> + mutex_unlock(&mgr->aux_lock);
> + if (i == 4)
> + return true;
> + return false;
> +}
> +
> +/**
> + * drm_dp_mst_dump_topology(): dump topology to seq file.
> + * @m: seq_file to dump output to
> + * @mgr: manager to dump current topology for.
> + *
> + * helper to dump MST topology to a seq file for debugfs.
> + */
> +void drm_dp_mst_dump_topology(struct seq_file *m,
> + struct drm_dp_mst_topology_mgr *mgr)
> +{
> + int i;
> + struct drm_dp_mst_port *port;
> + mutex_lock(&mgr->lock);
> + if (mgr->mst_primary)
> + drm_dp_mst_dump_mstb(m, mgr->mst_primary);
> +
> + /* dump VCPIs */
> + mutex_unlock(&mgr->lock);
> +
> + mutex_lock(&mgr->payload_lock);
> + seq_printf(m, "vcpi: %lx\n", mgr->payload_mask);
> +
> + for (i = 0; i < mgr->max_payloads; i++) {
> + if (mgr->proposed_vcpis[i]) {
> + port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, 
> vcpi);
> + seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, 
> port->vcpi.vcpi, port->vcpi.num_slots);
> + } else
> + seq_printf(m, "vcpi %d:unsed\n", i);
> + }
> + for (i = 0; i < mgr->max_payloads; i++) {
> + seq_printf(m, "payload %d: %d, %d, %d\n",
> + i,
> + mgr->payloads[i].payload_state,
> + mgr->payloads[i].start_slot,
> + mgr->payloads[i].num_slots);
> +
> +
> + }
> + mutex_unlock(&mgr->payload_lock);
> +
> + mutex_lock(&mgr->lock);
> + if (mgr->mst_primary) {
> + u8 buf[64];
> + bool bret;
> + int ret;
> + ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, 
> DP_RECEIVER_CAP_SIZE);
> + seq_printf(m, "dpcd: ");
> + for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
> + seq_printf(m, "%02x ", buf[i]);
> + seq_printf(m, "\n");
> + ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
> + seq_printf(m, "faux/mst: ");
> + for (i = 0; i < 2; i++)
> + seq_printf(m, "%02x ", buf[i]);
> + seq_printf(m, "\n");
> + ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
> + seq_printf(m, "mst ctrl: ");
> + for (i = 0; i < 1; i++)
> + seq_printf(m, "%02x ", buf[i]);
> + seq_printf(m, "\n");
> +
> + bret = dump_dp_payload_table(mgr, buf);
> + if (bret == true) {
> + seq_printf(m, "payload table: ");
> + for (i = 0; i < 63; i++)
> + seq_printf(m, "%02x ", buf[i]);
> + seq_printf(m, "\n");
> + }
> +
> + }
> +
> + mutex_unlock(&mgr->lock);
> +
> +}
> +EXPORT_SYMBOL(drm_dp_mst_dump_topology);
> +
> +static void drm_dp_tx_work(struct work_struct *work)
> +{
> + struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct 
> drm_dp_mst_topology_mgr, tx_work);
> +
> + mutex_lock(&mgr->qlock);
> + if (mgr->tx_down_in_progress)
> + process_single_down_tx_qlock(mgr);
> + mutex_unlock(&mgr->qlock);
> +}
> +
> +/**
> + * drm_dp_mst_topology_mgr_init - initialise a topology manager
> + * @mgr: manager struct to initialise
> + * @dev: device providing this structure - for i2c addition.
> + * @aux: DP helper aux channel to talk to this device
> + * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
> + * @max_payloads: maximum number of payloads this GPU can source
> + * @conn_base_id: the connector object ID the MST device is connected to.
> + *
> + * Return 0 for success, or negative error code on failure
> + */
> +int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
> + struct device *dev, struct drm_dp_aux *aux,
> + int max_dpcd_transaction_bytes,
> + int max_payloads, int conn_base_id)
> +{
> + mutex_init(&mgr->lock);
> + mutex_init(&mgr->qlock);
> + mutex_init(&mgr->aux_lock);
> + mutex_init(&mgr->payload_lock);
> + INIT_LIST_HEAD(&mgr->tx_msg_upq);
> + INIT_LIST_HEAD(&mgr->tx_msg_downq);
> + INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
> + INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
> + init_waitqueue_head(&mgr->tx_waitq);
> + mgr->dev = dev;
> + mgr->aux = aux;
> + mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
> + mgr->max_payloads = max_payloads;
> + mgr->conn_base_id = conn_base_id;
> + mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), 
> GFP_KERNEL);
> + if (!mgr->payloads)
> + return -ENOMEM;
> + mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct 
> drm_dp_vcpi *), GFP_KERNEL);
> + if (!mgr->proposed_vcpis)
> + return -ENOMEM;
> + set_bit(0, &mgr->payload_mask);
> + test_calc_pbn_mode();
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
> +
> +/**
> + * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
> + * @mgr: manager to destroy
> + */
> +void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
> +{
> + mutex_lock(&mgr->payload_lock);
> + kfree(mgr->payloads);
> + mgr->payloads = NULL;
> + kfree(mgr->proposed_vcpis);
> + mgr->proposed_vcpis = NULL;
> + mutex_unlock(&mgr->payload_lock);
> + mgr->dev = NULL;
> + mgr->aux = NULL;
> +}
> +EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
> +
> +/* I2C device */
> +static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct 
> i2c_msg *msgs,
> + int num)
> +{
> + struct drm_dp_aux *aux = adapter->algo_data;
> + struct drm_dp_mst_port *port = container_of(aux, struct 
> drm_dp_mst_port, aux);
> + struct drm_dp_mst_branch *mstb;
> + struct drm_dp_mst_topology_mgr *mgr = port->mgr;
> + unsigned int i;
> + bool reading = false;
> + struct drm_dp_sideband_msg_req_body msg;
> + struct drm_dp_sideband_msg_tx *txmsg = NULL;
> + int ret;
> +
> + mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
> + if (!mstb)
> + return -EREMOTEIO;
> +
> + /* construct i2c msg */
> + /* see if last msg is a read */
> + if (msgs[num - 1].flags & I2C_M_RD)
> + reading = true;
> +
> + if (!reading) {
> + DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
> + ret = -EIO;
> + goto out;
> + }
> +
> + msg.req_type = DP_REMOTE_I2C_READ;
> + msg.u.i2c_read.num_transactions = num - 1;
> + msg.u.i2c_read.port_number = port->port_num;
> + for (i = 0; i < num - 1; i++) {
> + msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
> + msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
> + memcpy(&msg.u.i2c_read.transactions[i].bytes, msgs[i].buf, msgs[i].len);
> + }
> + msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
> + msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
> +
> + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
> + if (!txmsg) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + txmsg->dst = mstb;
> + drm_dp_encode_sideband_req(&msg, txmsg);
> +
> + drm_dp_queue_down_tx(mgr, txmsg);
> +
> + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
> + if (ret > 0) {
> +
> + if (txmsg->reply.reply_type == 1) { /* got a NAK back */
> + ret = -EREMOTEIO;
> + goto out;
> + }
> + if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
> + ret = -EIO;
> + goto out;
> + }
> + memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, 
> msgs[num - 1].len);
> + ret = num;
> + }
> +out:
> + kfree(txmsg);
> + drm_dp_put_mst_branch_device(mstb);
> + return ret;
> +}
> +
> +static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
> + I2C_FUNC_SMBUS_READ_BLOCK_DATA |
> + I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> + I2C_FUNC_10BIT_ADDR;
> +}
> +
> +static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
> + .functionality = drm_dp_mst_i2c_functionality,
> + .master_xfer = drm_dp_mst_i2c_xfer,
> +};
> +
> +/**
> + * drm_dp_mst_register_i2c_bus() - register an I2C adapter for 
> I2C-over-AUX
> + * @aux: DisplayPort AUX channel
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
> +{
> + aux->ddc.algo = &drm_dp_mst_i2c_algo;
> + aux->ddc.algo_data = aux;
> + aux->ddc.retries = 3;
> +
> + aux->ddc.class = I2C_CLASS_DDC;
> + aux->ddc.owner = THIS_MODULE;
> + aux->ddc.dev.parent = aux->dev;
> + aux->ddc.dev.of_node = aux->dev->of_node;
> +
> + strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
> + sizeof(aux->ddc.name));
> +
> + return i2c_add_adapter(&aux->ddc);
> +}
> +
> +/**
> + * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
> + * @aux: DisplayPort AUX channel
> + */
> +static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
> +{
> + i2c_del_adapter(&aux->ddc);
> +}
> diff --git a/include/drm/drm_dp_mst_helper.h 
> b/include/drm/drm_dp_mst_helper.h
> new file mode 100644
> index 0000000..6626d1b
> --- /dev/null
> +++ b/include/drm/drm_dp_mst_helper.h
> @@ -0,0 +1,507 @@
> +/*
> + * Copyright © 2014 Red Hat.
> + *
> + * Permission to use, copy, modify, distribute, and sell this 
> software and its
> + * documentation for any purpose is hereby granted without fee, 
> provided that
> + * the above copyright notice appear in all copies and that both that 
> copyright
> + * notice and this permission notice appear in supporting 
> documentation, and
> + * that the name of the copyright holders not be used in advertising or
> + * publicity pertaining to distribution of the software without specific,
> + * written prior permission. The copyright holders make no 
> representations
> + * about the suitability of this software for any purpose. It is 
> provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS 
> SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, 
> INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 
> LOSS OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
> PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +#ifndef _DRM_DP_MST_HELPER_H_
> +#define _DRM_DP_MST_HELPER_H_
> +
> +#include <linux/types.h>
> +#include <drm/drm_dp_helper.h>
> +
> +struct drm_dp_mst_branch;
> +
> +/**
> + * struct drm_dp_vcpi - Virtual Channel Payload Identifer
> + * @vcpi: Virtual channel ID.
> + * @pbn: Payload Bandwidth Number for this channel
> + * @aligned_pbn: PBN aligned with slot size
> + * @num_slots: number of slots for this PBN
> + */
> +struct drm_dp_vcpi {
> + int vcpi;
> + int pbn;
> + int aligned_pbn;
> + int num_slots;
> +};
> +
> +/**
> + * struct drm_dp_mst_port - MST port
> + * @kref: reference count for this port.
> + * @guid_valid: for DP 1.2 devices if we have validated the GUID.
> + * @guid: guid for DP 1.2 device on this port.
> + * @port_num: port number
> + * @input: if this port is an input port.
> + * @mcs: message capability status - DP 1.2 spec.
> + * @ddps: DisplayPort Device Plug Status - DP 1.2
> + * @pdt: Peer Device Type
> + * @ldps: Legacy Device Plug Status
> + * @dpcd_rev: DPCD revision of device on this port
> + * @available_pbn: Available bandwidth for this port.
> + * @next: link to next port on this branch device
> + * @mstb: branch device attach below this port
> + * @aux: i2c aux transport to talk to device connected to this port.
> + * @parent: branch device parent of this port
> + * @vcpi: Virtual Channel Payload info for this port.
> + * @connector: DRM connector this port is connected to.
> + * @mgr: topology manager this port lives under.
> + *
> + * This structure represents an MST port endpoint on a device somewhere
> + * in the MST topology.
> + */
> +struct drm_dp_mst_port {
> + struct kref kref;
> +
> + /* if dpcd 1.2 device is on this port - its GUID info */
> + bool guid_valid;
> + u8 guid[16];
> +
> + u8 port_num;
> + bool input;
> + bool mcs;
> + bool ddps;
> + u8 pdt;
> + bool ldps;
> + u8 dpcd_rev;
> + uint16_t available_pbn;
> + struct list_head next;
> + struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port 
> has one */
> + struct drm_dp_aux aux; /* i2c bus for this port? */
> + struct drm_dp_mst_branch *parent;
> +
> + struct drm_dp_vcpi vcpi;
> + struct drm_connector *connector;
> + struct drm_dp_mst_topology_mgr *mgr;
> +};
> +
> +/**
> + * struct drm_dp_mst_branch - MST branch device.
> + * @kref: reference count for this port.
> + * @rad: Relative Address to talk to this branch device.
> + * @lct: Link count total to talk to this branch device.
> + * @num_ports: number of ports on the branch.
> + * @msg_slots: one bit per transmitted msg slot.
> + * @ports: linked list of ports on this branch.
> + * @port_parent: pointer to the port parent, NULL if toplevel.
> + * @mgr: topology manager for this branch device.
> + * @tx_slots: transmission slots for this device.
> + * @last_seqno: last sequence number used to talk to this.
> + * @link_address_sent: if a link address message has been sent to 
> this device yet.
> + *
> + * This structure represents an MST branch device, there is one
> + * primary branch device at the root, along with any others connected
> + * to downstream ports
> + */
> +struct drm_dp_mst_branch {
> + struct kref kref;
> + u8 rad[8];
> + u8 lct;
> + int num_ports;
> +
> + int msg_slots;
> + struct list_head ports;
> +
> + /* list of tx ops queue for this port */
> + struct drm_dp_mst_port *port_parent;
> + struct drm_dp_mst_topology_mgr *mgr;
> +
> + /* slots are protected by mstb->mgr->qlock */
> + struct drm_dp_sideband_msg_tx *tx_slots[2];
> + int last_seqno;
> + bool link_address_sent;
> +};
> +
> +
> +/* sideband msg header - not bit struct */
> +struct drm_dp_sideband_msg_hdr {
> + u8 lct;
> + u8 lcr;
> + u8 rad[8];
> + bool broadcast;
> + bool path_msg;
> + u8 msg_len;
> + bool somt;
> + bool eomt;
> + bool seqno;
> +};
> +
> +struct drm_dp_nak_reply {
> + u8 guid[16];
> + u8 reason;
> + u8 nak_data;
> +};
> +
> +struct drm_dp_link_address_ack_reply {
> + u8 guid[16];
> + u8 nports;
> + struct drm_dp_link_addr_reply_port {
> + bool input_port;
> + u8 peer_device_type;
> + u8 port_number;
> + bool mcs;
> + bool ddps;
> + bool legacy_device_plug_status;
> + u8 dpcd_revision;
> + u8 peer_guid[16];
> + bool num_sdp_streams;
> + bool num_sdp_stream_sinks;
> + } ports[16];
> +};
> +
> +struct drm_dp_remote_dpcd_read_ack_reply {
> + u8 port_number;
> + u8 num_bytes;
> + u8 bytes[255];
> +};
> +
> +struct drm_dp_remote_dpcd_write_ack_reply {
> + u8 port_number;
> +};
> +
> +struct drm_dp_remote_dpcd_write_nak_reply {
> + u8 port_number;
> + u8 reason;
> + u8 bytes_written_before_failure;
> +};
> +
> +struct drm_dp_remote_i2c_read_ack_reply {
> + u8 port_number;
> + u8 num_bytes;
> + u8 bytes[255];
> +};
> +
> +struct drm_dp_remote_i2c_read_nak_reply {
> + u8 port_number;
> + u8 nak_reason;
> + u8 i2c_nak_transaction;
> +};
> +
> +struct drm_dp_remote_i2c_write_ack_reply {
> + u8 port_number;
> +};
> +
> +
> +struct drm_dp_sideband_msg_rx {
> + u8 chunk[48];
> + u8 msg[256];
> + u8 curchunk_len;
> + u8 curchunk_idx; /* chunk we are parsing now */
> + u8 curchunk_hdrlen;
> + u8 curlen; /* total length of the msg */
> + bool have_somt;
> + bool have_eomt;
> + struct drm_dp_sideband_msg_hdr initial_hdr;
> +};
> +
> +
> +struct drm_dp_allocate_payload {
> + u8 port_number;
> + u8 number_sdp_streams;
> + u8 vcpi;
> + u16 pbn;
> + u8 sdp_stream_sink[8];
> +};
> +
> +struct drm_dp_allocate_payload_ack_reply {
> + u8 port_number;
> + u8 vcpi;
> + u16 allocated_pbn;
> +};
> +
> +struct drm_dp_connection_status_notify {
> + u8 guid[16];
> + u8 port_number;
> + bool legacy_device_plug_status;
> + bool displayport_device_plug_status;
> + bool message_capability_status;
> + bool input_port;
> + u8 peer_device_type;
> +};
> +
> +struct drm_dp_remote_dpcd_read {
> + u8 port_number;
> + u32 dpcd_address;
> + u8 num_bytes;
> +};
> +
> +struct drm_dp_remote_dpcd_write {
> + u8 port_number;
> + u32 dpcd_address;
> + u8 num_bytes;
> + u8 bytes[255];
> +};
> +
> +struct drm_dp_remote_i2c_read {
> + u8 num_transactions;
> + u8 port_number;
> + struct {
> + u8 i2c_dev_id;
> + u8 num_bytes;
> + u8 bytes[255];
> + u8 no_stop_bit;
> + u8 i2c_transaction_delay;
> + } transactions[4];
> + u8 read_i2c_device_id;
> + u8 num_bytes_read;
> +};
> +
> +struct drm_dp_remote_i2c_write {
> + u8 port_number;
> + u8 write_i2c_device_id;
> + u8 num_bytes;
> + u8 bytes[255];
> +};
> +
> +/* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
> +struct drm_dp_port_number_req {
> + u8 port_number;
> +};
> +
> +struct drm_dp_enum_path_resources_ack_reply {
> + u8 port_number;
> + u16 full_payload_bw_number;
> + u16 avail_payload_bw_number;
> +};
> +
> +/* covers POWER_DOWN_PHY, POWER_UP_PHY */
> +struct drm_dp_port_number_rep {
> + u8 port_number;
> +};
> +
> +struct drm_dp_query_payload {
> + u8 port_number;
> + u8 vcpi;
> +};
> +
> +struct drm_dp_resource_status_notify {
> + u8 port_number;
> + u8 guid[16];
> + u16 available_pbn;
> +};
> +
> +struct drm_dp_query_payload_ack_reply {
> + u8 port_number;
> + u8 allocated_pbn;
> +};
> +
> +struct drm_dp_sideband_msg_req_body {
> + u8 req_type;
> + union ack_req {
> + struct drm_dp_connection_status_notify conn_stat;
> + struct drm_dp_port_number_req port_num;
> + struct drm_dp_resource_status_notify resource_stat;
> +
> + struct drm_dp_query_payload query_payload;
> + struct drm_dp_allocate_payload allocate_payload;
> +
> + struct drm_dp_remote_dpcd_read dpcd_read;
> + struct drm_dp_remote_dpcd_write dpcd_write;
> +
> + struct drm_dp_remote_i2c_read i2c_read;
> + struct drm_dp_remote_i2c_write i2c_write;
> + } u;
> +};
> +
> +struct drm_dp_sideband_msg_reply_body {
> + u8 reply_type;
> + u8 req_type;
> + union ack_replies {
> + struct drm_dp_nak_reply nak;
> + struct drm_dp_link_address_ack_reply link_addr;
> + struct drm_dp_port_number_rep port_number;
> +
> + struct drm_dp_enum_path_resources_ack_reply path_resources;
> + struct drm_dp_allocate_payload_ack_reply allocate_payload;
> + struct drm_dp_query_payload_ack_reply query_payload;
> +
> + struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
> + struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
> + struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
> +
> + struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
> + struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
> + struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
> + } u;
> +};
> +
> +/* msg is queued to be put into a slot */
> +#define DRM_DP_SIDEBAND_TX_QUEUED 0
> +/* msg has started transmitting on a slot - still on msgq */
> +#define DRM_DP_SIDEBAND_TX_START_SEND 1
> +/* msg has finished transmitting on a slot - removed from msgq only 
> in slot */
> +#define DRM_DP_SIDEBAND_TX_SENT 2
> +/* msg has received a response - removed from slot */
> +#define DRM_DP_SIDEBAND_TX_RX 3
> +#define DRM_DP_SIDEBAND_TX_TIMEOUT 4
> +
> +struct drm_dp_sideband_msg_tx {
> + u8 msg[256];
> + u8 chunk[48];
> + u8 cur_offset;
> + u8 cur_len;
> + struct drm_dp_mst_branch *dst;
> + struct list_head next;
> + int seqno;
> + int state;
> + bool path_msg;
> + struct drm_dp_sideband_msg_reply_body reply;
> +};
> +
> +/* sideband msg handler */
> +struct drm_dp_mst_topology_mgr;
> +struct drm_dp_mst_topology_cbs {
> + /* create a connector for a port */
> + struct drm_connector *(*add_connector)(struct 
> drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *path);
> + void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_connector *connector);
> + void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);
> +
> +};
> +
> +#define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)
> +
> +#define DP_PAYLOAD_LOCAL 1
> +#define DP_PAYLOAD_REMOTE 2
> +#define DP_PAYLOAD_DELETE_LOCAL 3
> +
> +struct drm_dp_payload {
> + int payload_state;
> + int start_slot;
> + int num_slots;
> +};
> +
> +/**
> + * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
> + * @dev: device pointer for adding i2c devices etc.
> + * @cbs: callbacks for connector addition and destruction.
> + * @max_dpcd_transaction_bytes - maximum number of bytes to 
> read/write in one go.
> + * @aux: aux channel for the DP connector.
> + * @max_payloads: maximum number of payloads the GPU can generate.
> + * @conn_base_id: DRM connector ID this mgr is connected to.
> + * @down_rep_recv: msg receiver state for down replies.
> + * @up_req_recv: msg receiver state for up requests.
> + * @lock: protects mst state, primary, guid, dpcd.
> + * @aux_lock: protects aux channel.
> + * @mst_state: if this manager is enabled for an MST capable port.
> + * @mst_primary: pointer to the primary branch device.
> + * @guid_valid: GUID valid for the primary branch device.
> + * @guid: GUID for primary port.
> + * @dpcd: cache of DPCD for primary port.
> + * @pbn_div: PBN to slots divisor.
> + *
> + * This struct represents the toplevel displayport MST topology manager.
> + * There should be one instance of this for every MST capable DP 
> connector
> + * on the GPU.
> + */
> +struct drm_dp_mst_topology_mgr {
> +
> + struct device *dev;
> + struct drm_dp_mst_topology_cbs *cbs;
> + int max_dpcd_transaction_bytes;
> + struct drm_dp_aux *aux; /* auxch for this topology mgr to use */
> + int max_payloads;
> + int conn_base_id;
> +
> + /* only ever accessed from the workqueue - which should be serialised */
> + struct drm_dp_sideband_msg_rx down_rep_recv;
> + struct drm_dp_sideband_msg_rx up_req_recv;
> +
> + /* pointer to info about the initial MST device */
> + struct mutex lock; /* protects mst_state + primary + guid + dpcd */
> +
> + struct mutex aux_lock; /* protect access to the AUX */
> + bool mst_state;
> + struct drm_dp_mst_branch *mst_primary;
> + /* primary MST device GUID */
> + bool guid_valid;
> + u8 guid[16];
> + u8 dpcd[DP_RECEIVER_CAP_SIZE];
> + u8 sink_count;
> + int pbn_div;
> + int total_slots;
> + int avail_slots;
> + int total_pbn;
> +
> + /* messages to be transmitted */
> + /* qlock protects the upq/downq and in_progress,
> + the mstb tx_slots and txmsg->state once they are queued */
> + struct mutex qlock;
> + struct list_head tx_msg_downq;
> + struct list_head tx_msg_upq;
> + bool tx_down_in_progress;
> + bool tx_up_in_progress;
> +
> + /* payload info + lock for it */
> + struct mutex payload_lock;
> + struct drm_dp_vcpi **proposed_vcpis;
> + struct drm_dp_payload *payloads;
> + unsigned long payload_mask;
> +
> + wait_queue_head_t tx_waitq;
> + struct work_struct work;
> +
> + struct work_struct tx_work;
> +};
> +
> +int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 
> struct device *dev, struct drm_dp_aux *aux, int 
> max_dpcd_transaction_bytes, int max_payloads, int conn_base_id);
> +
> +void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr 
> *mgr);
> +
> +
> +int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr 
> *mgr, bool mst_state);
> +
> +
> +int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, 
> bool *handled);
> +
> +
> +enum drm_connector_status drm_dp_mst_detect_port(struct 
> drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
> +
> +struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 
> struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
> +
> +
> +int drm_dp_calc_pbn_mode(int clock, int bpp);
> +
> +
> +bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, 
> struct drm_dp_mst_port *port, int pbn, int *slots);
> +
> +
> +void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, 
> struct drm_dp_mst_port *port);
> +
> +
> +void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
> + struct drm_dp_mst_port *port);
> +
> +
> +int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
> + int pbn);
> +
> +
> +int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);
> +
> +
> +int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);
> +
> +int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
> +
> +void drm_dp_mst_dump_topology(struct seq_file *m,
> + struct drm_dp_mst_topology_mgr *mgr);
> +
> +void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr 
> *mgr);
> +int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
> +#endif
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 08/11] i915: split some DP modesetting code into a separate function

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

this is just prep work for mst support.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 20 +++++++++++++-------
 drivers/gpu/drm/i915/intel_drv.h |  1 +
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 0ad4e96..a5b8b76 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -364,6 +364,18 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
 	DRM_ERROR("FDI link training failed!\n");
 }
 
+void intel_ddi_mode_set_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+	struct intel_digital_port *intel_dig_port =
+		enc_to_dig_port(&encoder->base);
+
+	intel_dp->DP = intel_dig_port->saved_port_bits |
+		DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
+	intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);
+
+}
+
 static void intel_ddi_mode_set(struct intel_encoder *encoder)
 {
 	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
@@ -378,13 +390,7 @@ static void intel_ddi_mode_set(struct intel_encoder *encoder)
 	crtc->eld_vld = false;
 	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
-		struct intel_digital_port *intel_dig_port =
-			enc_to_dig_port(&encoder->base);
-
-		intel_dp->DP = intel_dig_port->saved_port_bits |
-			       DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
-		intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);
-
+		intel_ddi_mode_set_dp(encoder);
 		if (intel_dp->has_audio) {
 			DRM_DEBUG_DRIVER("DP audio on pipe %c on DDI\n",
 					 pipe_name(crtc->pipe));
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index b885df1..8e41cdc 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -683,6 +683,7 @@ void intel_ddi_fdi_disable(struct drm_crtc *crtc);
 void intel_ddi_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_config *pipe_config);
 
+void intel_ddi_mode_set_dp(struct intel_encoder *encoder);
 
 /* intel_display.c */
 const char *intel_output_name(int output);
-- 
1.9.0

Re: [PATCH 08/11] i915: split some DP modesetting code into a separate function

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 3325 bytes --]


Looks good to me.

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:55 PM
> From: Dave Airlie <airlied@redhat.com>
>
> this is just prep work for mst support.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/i915/intel_ddi.c | 20 +++++++++++++-------
> drivers/gpu/drm/i915/intel_drv.h | 1 +
> 2 files changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c 
> b/drivers/gpu/drm/i915/intel_ddi.c
> index 0ad4e96..a5b8b76 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -364,6 +364,18 @@ void hsw_fdi_link_train(struct drm_crtc *crtc)
> DRM_ERROR("FDI link training failed!\n");
> }
>
> +void intel_ddi_mode_set_dp(struct intel_encoder *encoder)
> +{
> + struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> + struct intel_digital_port *intel_dig_port =
> + enc_to_dig_port(&encoder->base);
> +
> + intel_dp->DP = intel_dig_port->saved_port_bits |
> + DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
> + intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);
> +
> +}
> +
> static void intel_ddi_mode_set(struct intel_encoder *encoder)
> {
> struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
> @@ -378,13 +390,7 @@ static void intel_ddi_mode_set(struct 
> intel_encoder *encoder)
> crtc->eld_vld = false;
> if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
> struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> - struct intel_digital_port *intel_dig_port =
> - enc_to_dig_port(&encoder->base);
> -
> - intel_dp->DP = intel_dig_port->saved_port_bits |
> - DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
> - intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);
> -
> + intel_ddi_mode_set_dp(encoder);
> if (intel_dp->has_audio) {
> DRM_DEBUG_DRIVER("DP audio on pipe %c on DDI\n",
> pipe_name(crtc->pipe));
> diff --git a/drivers/gpu/drm/i915/intel_drv.h 
> b/drivers/gpu/drm/i915/intel_drv.h
> index b885df1..8e41cdc 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -683,6 +683,7 @@ void intel_ddi_fdi_disable(struct drm_crtc *crtc);
> void intel_ddi_get_config(struct intel_encoder *encoder,
> struct intel_crtc_config *pipe_config);
>
> +void intel_ddi_mode_set_dp(struct intel_encoder *encoder);
>
> /* intel_display.c */
> const char *intel_output_name(int output);
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 09/11] drm/i915: check connector->encoder before using it.

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

DP MST will need connectors that aren't connected to specific
encoders, add some checks in advance to avoid oopses.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c  | 16 +++++++++-------
 drivers/gpu/drm/i915/i915_irq.c      |  4 ++++
 drivers/gpu/drm/i915/intel_display.c | 25 ++++++++++++++-----------
 3 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 1e83ae4..88e944f 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2279,13 +2279,15 @@ static void intel_connector_info(struct seq_file *m,
 		seq_printf(m, "\tCEA rev: %d\n",
 			   connector->display_info.cea_rev);
 	}
-	if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
-	    intel_encoder->type == INTEL_OUTPUT_EDP)
-		intel_dp_info(m, intel_connector);
-	else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
-		intel_hdmi_info(m, intel_connector);
-	else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
-		intel_lvds_info(m, intel_connector);
+	if (intel_encoder) {
+		if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
+		    intel_encoder->type == INTEL_OUTPUT_EDP)
+			intel_dp_info(m, intel_connector);
+		else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
+			intel_hdmi_info(m, intel_connector);
+		else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
+			intel_lvds_info(m, intel_connector);
+	}
 
 	seq_printf(m, "\tmodes:\n");
 	list_for_each_entry(mode, &connector->modes, head)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index afa5519..5852dee 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1016,6 +1016,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
 	dev_priv->hpd_event_bits = 0;
 	list_for_each_entry(connector, &mode_config->connector_list, head) {
 		intel_connector = to_intel_connector(connector);
+		if (!intel_connector->encoder)
+			continue;
 		intel_encoder = intel_connector->encoder;
 		if (intel_encoder->hpd_pin > HPD_NONE &&
 		    dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == HPD_MARK_DISABLED &&
@@ -1046,6 +1048,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
 
 	list_for_each_entry(connector, &mode_config->connector_list, head) {
 		intel_connector = to_intel_connector(connector);
+		if (!intel_connector->encoder)
+			continue;
 		intel_encoder = intel_connector->encoder;
 		if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
 			if (intel_encoder->hot_plug)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b39d036..75b2aaf 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4600,20 +4600,23 @@ static void intel_connector_check_state(struct intel_connector *connector)
 		     "wrong connector dpms state\n");
 		WARN(connector->base.encoder != &encoder->base,
 		     "active connector not linked to encoder\n");
-		WARN(!encoder->connectors_active,
-		     "encoder->connectors_active not set\n");
 
-		encoder_enabled = encoder->get_hw_state(encoder, &pipe);
-		WARN(!encoder_enabled, "encoder not enabled\n");
-		if (WARN_ON(!encoder->base.crtc))
-			return;
+		if (encoder) {
+			WARN(!encoder->connectors_active,
+			     "encoder->connectors_active not set\n");
+
+			encoder_enabled = encoder->get_hw_state(encoder, &pipe);
+			WARN(!encoder_enabled, "encoder not enabled\n");
+			if (WARN_ON(!encoder->base.crtc))
+				return;
 
-		crtc = encoder->base.crtc;
+			crtc = encoder->base.crtc;
 
-		WARN(!crtc->enabled, "crtc not enabled\n");
-		WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
-		WARN(pipe != to_intel_crtc(crtc)->pipe,
-		     "encoder active on the wrong pipe\n");
+			WARN(!crtc->enabled, "crtc not enabled\n");
+			WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
+			WARN(pipe != to_intel_crtc(crtc)->pipe,
+			     "encoder active on the wrong pipe\n");
+		}
 	}
 }
 
-- 
1.9.0

Re: [PATCH 09/11] drm/i915: check connector->encoder before using it.

[Todd Previte]

[-- Attachment #1.1: Type: text/plain, Size: 5118 bytes --]


Looks good.

Reviewed-by: Todd Previte <tprevite@gmail.com>

> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:55 PM
> From: Dave Airlie <airlied@redhat.com>
>
> DP MST will need connectors that aren't connected to specific
> encoders, add some checks in advance to avoid oopses.
>
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 16 +++++++++-------
> drivers/gpu/drm/i915/i915_irq.c | 4 ++++
> drivers/gpu/drm/i915/intel_display.c | 25 ++++++++++++++-----------
> 3 files changed, 27 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 1e83ae4..88e944f 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2279,13 +2279,15 @@ static void intel_connector_info(struct 
> seq_file *m,
> seq_printf(m, "\tCEA rev: %d\n",
> connector->display_info.cea_rev);
> }
> - if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
> - intel_encoder->type == INTEL_OUTPUT_EDP)
> - intel_dp_info(m, intel_connector);
> - else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
> - intel_hdmi_info(m, intel_connector);
> - else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
> - intel_lvds_info(m, intel_connector);
> + if (intel_encoder) {
> + if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
> + intel_encoder->type == INTEL_OUTPUT_EDP)
> + intel_dp_info(m, intel_connector);
> + else if (intel_encoder->type == INTEL_OUTPUT_HDMI)
> + intel_hdmi_info(m, intel_connector);
> + else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
> + intel_lvds_info(m, intel_connector);
> + }
>
> seq_printf(m, "\tmodes:\n");
> list_for_each_entry(mode, &connector->modes, head)
> diff --git a/drivers/gpu/drm/i915/i915_irq.c 
> b/drivers/gpu/drm/i915/i915_irq.c
> index afa5519..5852dee 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1016,6 +1016,8 @@ static void i915_hotplug_work_func(struct 
> work_struct *work)
> dev_priv->hpd_event_bits = 0;
> list_for_each_entry(connector, &mode_config->connector_list, head) {
> intel_connector = to_intel_connector(connector);
> + if (!intel_connector->encoder)
> + continue;
> intel_encoder = intel_connector->encoder;
> if (intel_encoder->hpd_pin > HPD_NONE &&
> dev_priv->hpd_stats[intel_encoder->hpd_pin].hpd_mark == 
> HPD_MARK_DISABLED &&
> @@ -1046,6 +1048,8 @@ static void i915_hotplug_work_func(struct 
> work_struct *work)
>
> list_for_each_entry(connector, &mode_config->connector_list, head) {
> intel_connector = to_intel_connector(connector);
> + if (!intel_connector->encoder)
> + continue;
> intel_encoder = intel_connector->encoder;
> if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
> if (intel_encoder->hot_plug)
> diff --git a/drivers/gpu/drm/i915/intel_display.c 
> b/drivers/gpu/drm/i915/intel_display.c
> index b39d036..75b2aaf 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4600,20 +4600,23 @@ static void intel_connector_check_state(struct 
> intel_connector *connector)
> "wrong connector dpms state\n");
> WARN(connector->base.encoder != &encoder->base,
> "active connector not linked to encoder\n");
> - WARN(!encoder->connectors_active,
> - "encoder->connectors_active not set\n");
>
> - encoder_enabled = encoder->get_hw_state(encoder, &pipe);
> - WARN(!encoder_enabled, "encoder not enabled\n");
> - if (WARN_ON(!encoder->base.crtc))
> - return;
> + if (encoder) {
> + WARN(!encoder->connectors_active,
> + "encoder->connectors_active not set\n");
> +
> + encoder_enabled = encoder->get_hw_state(encoder, &pipe);
> + WARN(!encoder_enabled, "encoder not enabled\n");
> + if (WARN_ON(!encoder->base.crtc))
> + return;
>
> - crtc = encoder->base.crtc;
> + crtc = encoder->base.crtc;
>
> - WARN(!crtc->enabled, "crtc not enabled\n");
> - WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
> - WARN(pipe != to_intel_crtc(crtc)->pipe,
> - "encoder active on the wrong pipe\n");
> + WARN(!crtc->enabled, "crtc not enabled\n");
> + WARN(!to_intel_crtc(crtc)->active, "crtc not active\n");
> + WARN(pipe != to_intel_crtc(crtc)->pipe,
> + "encoder active on the wrong pipe\n");
> + }
> }
> }
>
> Dave Airlie <mailto:airlied@gmail.com>
> Tuesday, May 20, 2014 7:54 PM
> Hey,
>
> So this set is pretty close to what I think we should be merging 
> initially,
>
> Since the last set, it makes fbcon and suspend/resume work a lot better,
>
> I've also fixed a couple of bugs in -intel that make things work a lot
> better.
>
> I've bashed on this a bit using kms-flip from intel-gpu-tools, hacked
> to add 3 monitor support.
>
> It still generates a fair few i915 state checker backtraces, and some
> of them are fairly hard to work out, it might be we should just tone
> down the state checker for encoders/connectors with no actual hw backing
> them.
>
> Dave.
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

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[PATCH 10/11] i915: add DP 1.2 MST support (v0.5)

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

This adds DP 1.2 MST support on Haswell systems.

Notes:
a) this reworks irq handling for DP MST ports, so that we can
avoid the mode config locking in the current hpd handlers, as
we need to process up/down msgs at a better time.

b) it introduces a new MST output type.

c) it really annoys the state checker, as the connector that is
connected at the start, goes into disconnected, and its encoder
it active, and things blow up, need to look into how to solve that.

d) the intel userspace driver needs changes to use this, -modesetting
should work okay.

e) it might contain a race condition big enough to eat you.

f) its hardcoded to 4 lanes 5.4Ghz. - TODO.

Changes since v0.1:
use PORT_PCH_HOTPLUG to detect short vs long pulses
add a workqueue to deal with digital events as they can get blocked on the
main workqueue beyong mode_config mutex
fix a bunch of modeset checker warnings
acks irqs in the driver
cleanup the MST encoders

Changes since v0.2:
check irq status again in work handler
move around bring up and tear down to fix DPMS on/off
use path properties.

Changes since v0.3:
updates for mst apis
more state checker fixes
irq handling improvements
fbcon handling support
improved reference counting of link - fixes redocking.

Changes since v0.4:
handle gpu reset hpd reinit without oopsing
check link status on HPD irqs
fix suspend/resume

TODO:
possibly further state checker fixes

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/i915/Makefile         |   1 +
 drivers/gpu/drm/i915/i915_dma.c       |  10 +
 drivers/gpu/drm/i915/i915_drv.c       |  13 +-
 drivers/gpu/drm/i915/i915_drv.h       |  14 +
 drivers/gpu/drm/i915/i915_irq.c       | 110 ++++++-
 drivers/gpu/drm/i915/intel_ddi.c      | 114 +++++--
 drivers/gpu/drm/i915/intel_display.c  |  59 +++-
 drivers/gpu/drm/i915/intel_dp.c       | 230 ++++++++++++++-
 drivers/gpu/drm/i915/intel_dp_mst.c   | 538 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h      |  45 ++-
 drivers/gpu/drm/i915/intel_fbdev.c    |   5 +
 drivers/gpu/drm/i915/intel_opregion.c |   1 +
 12 files changed, 1091 insertions(+), 49 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_dp_mst.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index b1445b7..6cf2b95 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -52,6 +52,7 @@ i915-y += dvo_ch7017.o \
 	  intel_crt.o \
 	  intel_ddi.o \
 	  intel_dp.o \
+	  intel_dp_mst.o \
 	  intel_dsi_cmd.o \
 	  intel_dsi.o \
 	  intel_dsi_pll.o \
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 58f2c46..3040869 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1677,6 +1677,13 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 		goto out_mtrrfree;
 	}
 
+	dev_priv->dp_wq = alloc_ordered_workqueue("i915-dp", 0);
+	if (dev_priv->dp_wq == NULL) {
+		DRM_ERROR("Failed to create our dp workqueue.\n");
+		ret = -ENOMEM;
+		goto out_freewq;
+	}
+
 	intel_irq_init(dev);
 	intel_uncore_sanitize(dev);
 
@@ -1752,6 +1759,8 @@ out_gem_unload:
 	intel_teardown_gmbus(dev);
 	intel_teardown_mchbar(dev);
 	pm_qos_remove_request(&dev_priv->pm_qos);
+	destroy_workqueue(dev_priv->dp_wq);
+out_freewq:
 	destroy_workqueue(dev_priv->wq);
 out_mtrrfree:
 	arch_phys_wc_del(dev_priv->gtt.mtrr);
@@ -1856,6 +1865,7 @@ int i915_driver_unload(struct drm_device *dev)
 	intel_teardown_gmbus(dev);
 	intel_teardown_mchbar(dev);
 
+	destroy_workqueue(dev_priv->dp_wq);
 	destroy_workqueue(dev_priv->wq);
 	pm_qos_remove_request(&dev_priv->pm_qos);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 254b323..6b18779 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -447,7 +447,6 @@ static int i915_drm_freeze(struct drm_device *dev)
 
 		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);
 
-		drm_irq_uninstall(dev);
 		dev_priv->enable_hotplug_processing = false;
 		/*
 		 * Disable CRTCs directly since we want to preserve sw state
@@ -458,6 +457,9 @@ static int i915_drm_freeze(struct drm_device *dev)
 			dev_priv->display.crtc_disable(crtc);
 		mutex_unlock(&dev->mode_config.mutex);
 
+		intel_dp_mst_suspend(dev);
+		drm_irq_uninstall(dev);
+
 		intel_modeset_suspend_hw(dev);
 	}
 
@@ -578,6 +580,15 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
 
 		intel_modeset_init_hw(dev);
 
+		{
+			unsigned long irqflags;
+			spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+			if (dev_priv->display.hpd_irq_setup)
+				dev_priv->display.hpd_irq_setup(dev);
+			spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+		}
+
+		intel_dp_mst_resume(dev);
 		drm_modeset_lock_all(dev);
 		intel_modeset_setup_hw_state(dev, true);
 		drm_modeset_unlock_all(dev);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7d6acb4..b3b5864c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1468,6 +1468,18 @@ struct drm_i915_private {
 
 	struct i915_runtime_pm pm;
 
+	struct intel_digital_port *hpd_irq_port[I915_MAX_PORTS];
+	u32 hpd_port;
+	struct work_struct dig_port_work;
+	/*
+	 * if we get a HPD irq from DP and a HPD irq from non-DP
+	 * the non-DP HPD could block the workqueue on a mode config
+	 * mutex getting, that userspace may have taken. However
+	 * userspace is waiting on the DP workqueue to run which is
+	 * blocked behind the non-DP one.
+	 */
+	struct workqueue_struct *dp_wq;
+
 	/* Old dri1 support infrastructure, beware the dragons ya fools entering
 	 * here! */
 	struct i915_dri1_state dri1;
@@ -1999,6 +2011,8 @@ i915_disable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
 
 void valleyview_enable_display_irqs(struct drm_i915_private *dev_priv);
 void valleyview_disable_display_irqs(struct drm_i915_private *dev_priv);
+bool intel_hpd_irq_event(struct drm_device *dev,
+			 struct drm_connector *connector);
 
 /* i915_gem.c */
 int i915_gem_init_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 5852dee..dd151b9 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -963,8 +963,8 @@ static int i915_get_vblank_timestamp(struct drm_device *dev, int pipe,
 						     &to_intel_crtc(crtc)->config.adjusted_mode);
 }
 
-static bool intel_hpd_irq_event(struct drm_device *dev,
-				struct drm_connector *connector)
+bool intel_hpd_irq_event(struct drm_device *dev,
+			 struct drm_connector *connector)
 {
 	enum drm_connector_status old_status;
 
@@ -984,6 +984,71 @@ static bool intel_hpd_irq_event(struct drm_device *dev,
 	return true;
 }
 
+static int port_to_hotplug_shift(enum port port)
+{
+	switch (port) {
+	case PORT_A:
+	case PORT_E:
+	default:
+		return -1;
+	case PORT_B:
+		return 0;
+	case PORT_C:
+		return 8;
+	case PORT_D:
+		return 16;
+	}
+}
+static void i915_digport_work_func(struct work_struct *work)
+{
+	struct drm_i915_private *dev_priv =
+		container_of(work, struct drm_i915_private, dig_port_work);
+	unsigned long irqflags;
+	u32 port_bits;
+	struct intel_digital_port *digport;
+	int i, ret;
+	u32 old_bits = 0;
+	u32 hotplug_reg, hpshift;
+	bool long_hpd = false;
+	spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+	port_bits = dev_priv->hpd_port;
+	dev_priv->hpd_port = 0;
+
+	hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
+	I915_WRITE(PCH_PORT_HOTPLUG, hotplug_reg);
+
+	spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
+	for (i = 0; i < I915_MAX_PORTS; i++) {
+		if (port_bits & (1 << i)) {
+			digport = dev_priv->hpd_irq_port[i];
+
+			hpshift = port_to_hotplug_shift(i);
+
+			/* if we have no HPD bits for this */
+			if (!((hotplug_reg >> hpshift) & PORTB_HOTPLUG_STATUS_MASK)) {
+				DRM_DEBUG_KMS("got not regs for port %d %08x\n", i, hotplug_reg);
+				continue;
+			}
+
+			long_hpd = (hotplug_reg >> hpshift) & PORTB_HOTPLUG_LONG_DETECT;
+
+			ret = intel_dp_handle_hpd_irq(digport, long_hpd);
+			if (ret == 1) {
+				/* if we get 1 fallback to old school hpd */
+				old_bits |= (1 << digport->base.hpd_pin);
+			}
+		}
+	}
+
+	if (old_bits) {
+		spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+		dev_priv->hpd_event_bits = old_bits;
+		spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+		schedule_work(&dev_priv->hotplug_work);
+	}
+}
+
 /*
  * Handle hotplug events outside the interrupt handler proper.
  */
@@ -1381,14 +1446,29 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 #define HPD_STORM_DETECT_PERIOD 1000
 #define HPD_STORM_THRESHOLD 5
 
+static inline enum port get_port_from_pin(enum hpd_pin pin)
+{
+	switch (pin) {
+	case HPD_PORT_B:
+		return PORT_B;
+	case HPD_PORT_C:
+		return PORT_C;
+	case HPD_PORT_D:
+		return PORT_D;
+	default:
+		return PORT_A; /* no hpd */
+	}
+}
+
 static inline void intel_hpd_irq_handler(struct drm_device *dev,
 					 u32 hotplug_trigger,
 					 const u32 *hpd)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int i;
+	enum port port;
 	bool storm_detected = false;
-
+	bool queue_dig = false, queue_hp = false;
 	if (!hotplug_trigger)
 		return;
 
@@ -1397,6 +1477,19 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 
 	spin_lock(&dev_priv->irq_lock);
 	for (i = 1; i < HPD_NUM_PINS; i++) {
+		if (!(hpd[i] & hotplug_trigger))
+			continue;
+
+		port = get_port_from_pin(i);
+		if (port && dev_priv->hpd_irq_port[port]) {
+			DRM_DEBUG_DRIVER("digital hpd port %d\n", port);
+			dev_priv->hpd_port |= (1 << port);
+			hotplug_trigger &= ~hpd[i];
+			queue_dig = true;
+		}
+	}
+
+	for (i = 1; i < HPD_NUM_PINS; i++) {
 
 		if (hpd[i] & hotplug_trigger &&
 		    dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED) {
@@ -1418,6 +1511,7 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 			continue;
 
 		dev_priv->hpd_event_bits |= (1 << i);
+		queue_hp = true;
 		if (!time_in_range(jiffies, dev_priv->hpd_stats[i].hpd_last_jiffies,
 				   dev_priv->hpd_stats[i].hpd_last_jiffies
 				   + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD))) {
@@ -1446,7 +1540,10 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 	 * queue for otherwise the flush_work in the pageflip code will
 	 * deadlock.
 	 */
-	schedule_work(&dev_priv->hotplug_work);
+	if (queue_dig)
+		queue_work(dev_priv->dp_wq, &dev_priv->dig_port_work);
+	if (queue_hp)
+		schedule_work(&dev_priv->hotplug_work);
 }
 
 static void gmbus_irq_handler(struct drm_device *dev)
@@ -4014,6 +4111,7 @@ void intel_irq_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	INIT_WORK(&dev_priv->dig_port_work, i915_digport_work_func);
 	INIT_WORK(&dev_priv->hotplug_work, i915_hotplug_work_func);
 	INIT_WORK(&dev_priv->gpu_error.work, i915_error_work_func);
 	INIT_WORK(&dev_priv->rps.work, gen6_pm_rps_work);
@@ -4109,7 +4207,9 @@ void intel_hpd_init(struct drm_device *dev)
 	list_for_each_entry(connector, &mode_config->connector_list, head) {
 		struct intel_connector *intel_connector = to_intel_connector(connector);
 		connector->polled = intel_connector->polled;
-		if (!connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE)
+		if (connector->encoder && !connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE)
+			connector->polled = DRM_CONNECTOR_POLL_HPD;
+		if (intel_connector->mst_port)
 			connector->polled = DRM_CONNECTOR_POLL_HPD;
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index a5b8b76..1cac461 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -116,7 +116,10 @@ enum port intel_ddi_get_encoder_port(struct intel_encoder *intel_encoder)
 	struct drm_encoder *encoder = &intel_encoder->base;
 	int type = intel_encoder->type;
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP ||
+	if (type == INTEL_OUTPUT_DP_MST) {
+		struct intel_digital_port *intel_dig_port = enc_to_mst(encoder)->primary;
+		return intel_dig_port->port;
+	} else if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP ||
 	    type == INTEL_OUTPUT_HDMI || type == INTEL_OUTPUT_UNKNOWN) {
 		struct intel_digital_port *intel_dig_port =
 			enc_to_dig_port(encoder);
@@ -211,6 +214,19 @@ void intel_prepare_ddi(struct drm_device *dev)
 		intel_prepare_ddi_buffers(dev, port);
 }
 
+void intel_ddi_force_act(struct intel_encoder *encoder, bool state)
+{
+	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+	enum port port = intel_ddi_get_encoder_port(encoder);
+	u32 val;
+	val = I915_READ(DP_TP_CTL(port));
+	if (state == true)
+		val |= DP_TP_CTL_FORCE_ACT;
+	else
+		val &= ~DP_TP_CTL_FORCE_ACT;
+	I915_WRITE(DP_TP_CTL(port), val);
+}
+
 static const long hsw_ddi_buf_ctl_values[] = {
 	DDI_BUF_EMP_400MV_0DB_HSW,
 	DDI_BUF_EMP_400MV_3_5DB_HSW,
@@ -673,8 +689,8 @@ static int intel_ddi_calc_wrpll_link(struct drm_i915_private *dev_priv,
 	return (refclk * n * 100) / (p * r);
 }
 
-static void intel_ddi_clock_get(struct intel_encoder *encoder,
-				struct intel_crtc_config *pipe_config)
+void intel_ddi_clock_get(struct intel_encoder *encoder,
+			 struct intel_crtc_config *pipe_config)
 {
 	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
 	enum port port = intel_ddi_get_encoder_port(encoder);
@@ -795,6 +811,20 @@ intel_ddi_calculate_wrpll(int clock /* in Hz */,
 	*r2_out = best.r2;
 }
 
+static int link_bw_to_pll_sel(int link_bw)
+{
+	switch (link_bw) {
+	case DP_LINK_BW_1_62:
+		return PORT_CLK_SEL_LCPLL_810;
+	case DP_LINK_BW_2_7:
+		return PORT_CLK_SEL_LCPLL_1350;
+	case DP_LINK_BW_5_4:
+		return PORT_CLK_SEL_LCPLL_2700;
+	default:
+		return -1;
+	}
+}
+
 /*
  * Tries to find a PLL for the CRTC. If it finds, it increases the refcount and
  * stores it in intel_crtc->ddi_pll_sel, so other mode sets won't be able to
@@ -814,20 +844,19 @@ bool intel_ddi_pll_select(struct intel_crtc *intel_crtc)
 
 	intel_ddi_put_crtc_pll(crtc);
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
+	if (type == INTEL_OUTPUT_DP_MST) {
+		struct intel_dp_mst_encoder *intel_mst = enc_to_mst(encoder);
+		intel_crtc->ddi_pll_sel = link_bw_to_pll_sel(intel_mst->primary->dp.link_bw);
+		if (intel_crtc->ddi_pll_sel == -1) {
+			DRM_ERROR("Link bandwidth %d unsupported\n",
+				  intel_mst->primary->dp.link_bw);
+			return false;
+		}
+	} else if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
-		switch (intel_dp->link_bw) {
-		case DP_LINK_BW_1_62:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_810;
-			break;
-		case DP_LINK_BW_2_7:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_1350;
-			break;
-		case DP_LINK_BW_5_4:
-			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_LCPLL_2700;
-			break;
-		default:
+		intel_crtc->ddi_pll_sel = link_bw_to_pll_sel(intel_dp->link_bw);
+		if (intel_crtc->ddi_pll_sel == -1) {
 			DRM_ERROR("Link bandwidth %d unsupported\n",
 				  intel_dp->link_bw);
 			return false;
@@ -981,8 +1010,7 @@ void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
 	int type = intel_encoder->type;
 	uint32_t temp;
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
-
+	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP || type == INTEL_OUTPUT_DP_MST) {
 		temp = TRANS_MSA_SYNC_CLK;
 		switch (intel_crtc->config.pipe_bpp) {
 		case 18:
@@ -1004,6 +1032,21 @@ void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
 	}
 }
 
+void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state)
+{
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
+	uint32_t temp;
+	temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+	if (state == true)
+		temp |= TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
+	else
+		temp &= ~TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
+	I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
+}
+
 void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -1083,7 +1126,19 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 		   type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
-		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
+		if (intel_dp->is_mst) {
+			temp |= TRANS_DDI_MODE_SELECT_DP_MST;
+		} else
+			temp |= TRANS_DDI_MODE_SELECT_DP_SST;
+
+		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
+	} else if (type == INTEL_OUTPUT_DP_MST) {
+		struct intel_dp *intel_dp = &enc_to_mst(encoder)->primary->dp;
+
+		if (intel_dp->is_mst) {
+			temp |= TRANS_DDI_MODE_SELECT_DP_MST;
+		} else
+			temp |= TRANS_DDI_MODE_SELECT_DP_SST;
 
 		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
 	} else {
@@ -1100,7 +1155,7 @@ void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv,
 	uint32_t reg = TRANS_DDI_FUNC_CTL(cpu_transcoder);
 	uint32_t val = I915_READ(reg);
 
-	val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK);
+	val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK | TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
 	val |= TRANS_DDI_PORT_NONE;
 	I915_WRITE(reg, val);
 }
@@ -1139,8 +1194,11 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
 	case TRANS_DDI_MODE_SELECT_DP_SST:
 		if (type == DRM_MODE_CONNECTOR_eDP)
 			return true;
-	case TRANS_DDI_MODE_SELECT_DP_MST:
 		return (type == DRM_MODE_CONNECTOR_DisplayPort);
+	case TRANS_DDI_MODE_SELECT_DP_MST:
+		/* if the transcoder is in MST state then 
+		 * connector isn't connected */
+		return false;
 
 	case TRANS_DDI_MODE_SELECT_FDI:
 		return (type == DRM_MODE_CONNECTOR_VGA);
@@ -1192,6 +1250,9 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 
 			if ((tmp & TRANS_DDI_PORT_MASK)
 			    == TRANS_DDI_SELECT_PORT(port)) {
+				if ((tmp & TRANS_DDI_MODE_SELECT_MASK) == TRANS_DDI_MODE_SELECT_DP_MST)
+					return false;
+
 				*pipe = i;
 				return true;
 			}
@@ -1498,10 +1559,15 @@ void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder)
 			intel_wait_ddi_buf_idle(dev_priv, port);
 	}
 
-	val = DP_TP_CTL_ENABLE | DP_TP_CTL_MODE_SST |
+	val = DP_TP_CTL_ENABLE |
 	      DP_TP_CTL_LINK_TRAIN_PAT1 | DP_TP_CTL_SCRAMBLE_DISABLE;
-	if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
-		val |= DP_TP_CTL_ENHANCED_FRAME_ENABLE;
+	if (intel_dp->is_mst)
+		val |= DP_TP_CTL_MODE_MST;
+	else {
+		val |= DP_TP_CTL_MODE_SST;
+		if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
+			val |= DP_TP_CTL_ENHANCED_FRAME_ENABLE;
+	}
 	I915_WRITE(DP_TP_CTL(port), val);
 	POSTING_READ(DP_TP_CTL(port));
 
@@ -1732,6 +1798,8 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 	intel_encoder->cloneable = 0;
 	intel_encoder->hot_plug = intel_ddi_hot_plug;
 
+	dev_priv->hpd_irq_port[port] = intel_dig_port;
+
 	if (init_dp)
 		dp_connector = intel_ddi_init_dp_connector(intel_dig_port);
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 75b2aaf..dfcc78e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -56,6 +56,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
 				  struct drm_mode_fb_cmd2 *mode_cmd,
 				  struct drm_i915_gem_object *obj);
 
+static struct intel_encoder *intel_find_encoder(struct intel_connector *connector, int pipe)
+{
+	if (!connector->mst_port)
+		return connector->encoder;
+	else
+		return &connector->mst_port->mst_encoders[pipe]->base;
+}
+
 typedef struct {
 	int	min, max;
 } intel_range_t;
@@ -3821,6 +3829,9 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
 	if (intel_crtc->config.has_pch_encoder)
 		lpt_pch_enable(crtc);
 
+	if (intel_crtc->config.dp_encoder_is_mst)
+		intel_ddi_set_vc_payload_alloc(crtc, true);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
 		encoder->enable(encoder);
 		intel_opregion_notify_encoder(encoder, true);
@@ -3869,6 +3880,9 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
 	intel_disable_pipe(dev_priv, pipe);
 
+	if (intel_crtc->config.dp_encoder_is_mst)
+		intel_ddi_set_vc_payload_alloc(crtc, false);
+
 	ironlake_pfit_disable(intel_crtc);
 
 	for_each_encoder_on_crtc(dev, crtc, encoder)
@@ -4038,6 +4052,23 @@ static void i9xx_pfit_enable(struct intel_crtc *crtc)
 	for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++)	\
 		if ((1 << (domain)) & (mask))
 
+enum intel_display_power_domain port_to_power_domain(enum port port)
+{
+	switch (port) {
+	case PORT_A:
+		return POWER_DOMAIN_PORT_DDI_A_4_LANES;
+	case PORT_B:
+		return POWER_DOMAIN_PORT_DDI_B_4_LANES;
+	case PORT_C:
+		return POWER_DOMAIN_PORT_DDI_C_4_LANES;
+	case PORT_D:
+		return POWER_DOMAIN_PORT_DDI_D_4_LANES;
+	default:
+		WARN_ON_ONCE(1);
+		return POWER_DOMAIN_PORT_OTHER;
+	}
+}
+
 enum intel_display_power_domain
 intel_display_port_power_domain(struct intel_encoder *intel_encoder)
 {
@@ -4052,19 +4083,10 @@ intel_display_port_power_domain(struct intel_encoder *intel_encoder)
 	case INTEL_OUTPUT_HDMI:
 	case INTEL_OUTPUT_EDP:
 		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
-		switch (intel_dig_port->port) {
-		case PORT_A:
-			return POWER_DOMAIN_PORT_DDI_A_4_LANES;
-		case PORT_B:
-			return POWER_DOMAIN_PORT_DDI_B_4_LANES;
-		case PORT_C:
-			return POWER_DOMAIN_PORT_DDI_C_4_LANES;
-		case PORT_D:
-			return POWER_DOMAIN_PORT_DDI_D_4_LANES;
-		default:
-			WARN_ON_ONCE(1);
-			return POWER_DOMAIN_PORT_OTHER;
-		}
+		return port_to_power_domain(intel_dig_port->port);
+	case INTEL_OUTPUT_DP_MST:
+		intel_dig_port = enc_to_mst(&intel_encoder->base)->primary;
+		return port_to_power_domain(intel_dig_port->port);
 	case INTEL_OUTPUT_ANALOG:
 		return POWER_DOMAIN_PORT_CRT;
 	case INTEL_OUTPUT_DSI:
@@ -10203,7 +10225,7 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 		 * for them. */
 		for (ro = 0; ro < set->num_connectors; ro++) {
 			if (set->connectors[ro] == &connector->base) {
-				connector->new_encoder = connector->encoder;
+				connector->new_encoder = intel_find_encoder(connector, to_intel_crtc(set->crtc)->pipe);
 				break;
 			}
 		}
@@ -10249,7 +10271,7 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 					 new_crtc)) {
 			return -EINVAL;
 		}
-		connector->encoder->new_crtc = to_intel_crtc(new_crtc);
+		connector->new_encoder->new_crtc = to_intel_crtc(new_crtc);
 
 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 			connector->base.base.id,
@@ -10283,7 +10305,12 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 		}
 	}
 	/* Now we've also updated encoder->new_crtc for all encoders. */
-
+	list_for_each_entry(connector, &dev->mode_config.connector_list,
+			    base.head) {
+		if (connector->new_encoder)
+			if (connector->new_encoder != connector->encoder)
+				connector->encoder = connector->new_encoder;
+	}
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list,
 			    base.head) {
 		crtc->new_enabled = false;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 44df493..ea848ac 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -701,8 +701,9 @@ intel_dp_connector_unregister(struct intel_connector *intel_connector)
 {
 	struct intel_dp *intel_dp = intel_attached_dp(&intel_connector->base);
 
-	sysfs_remove_link(&intel_connector->base.kdev->kobj,
-			  intel_dp->aux.ddc.dev.kobj.name);
+	if (!intel_connector->mst_port)
+		sysfs_remove_link(&intel_connector->base.kdev->kobj,
+				  intel_dp->aux.ddc.dev.kobj.name);
 	intel_connector_unregister(intel_connector);
 }
 
@@ -2892,6 +2893,33 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
 	edp_panel_vdd_off(intel_dp, false);
 }
 
+static bool
+intel_dp_probe_mst(struct intel_dp *intel_dp)
+{
+	u8 buf[1];
+
+	if (!intel_dp->can_mst)
+		return false;
+
+	if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
+		return false;
+
+	_edp_panel_vdd_on(intel_dp);
+	if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
+		if (buf[0] & DP_MST_CAP) {
+			DRM_DEBUG_KMS("Sink is MST capable\n");
+			intel_dp->is_mst = true;
+		} else {
+			DRM_DEBUG_KMS("Sink is not MST capable\n");
+			intel_dp->is_mst = false;
+		}
+	}
+	edp_panel_vdd_off(intel_dp, false);
+
+	drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
+	return intel_dp->is_mst;
+}
+
 int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
 {
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
@@ -2929,6 +2957,20 @@ intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
 				       sink_irq_vector, 1) == 1;
 }
 
+static bool
+intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
+{
+	int ret;
+
+	ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
+					     DP_SINK_COUNT_ESI,
+					     sink_irq_vector, 14);
+	if (ret != 14)
+		return false;
+
+	return true;
+}
+
 static void
 intel_dp_handle_test_request(struct intel_dp *intel_dp)
 {
@@ -2944,6 +2986,68 @@ intel_dp_handle_test_request(struct intel_dp *intel_dp)
  *  3. Use Link Training from 2.5.3.3 and 3.5.1.3
  *  4. Check link status on receipt of hot-plug interrupt
  */
+static int
+intel_dp_check_mst_status(struct intel_dp *intel_dp)
+{
+	bool bret;
+
+	if (intel_dp->is_mst) {
+		u8 esi[16] = { 0 };
+		int ret = 0;
+		int retry;
+		bool handled;
+		mutex_lock(&intel_dp->mst_mgr.aux_lock);
+		bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
+		mutex_unlock(&intel_dp->mst_mgr.aux_lock);
+	go_again:
+		if (bret == true) {
+
+			/* check link status - esi[10] = 0x200c */
+			if (intel_dp->active_mst_links && !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
+				DRM_DEBUG_KMS("channel EQ not ok, retraining\n");
+				intel_dp_start_link_train(intel_dp);
+				intel_dp_complete_link_train(intel_dp);
+				intel_dp_stop_link_train(intel_dp);
+			}
+
+			DRM_DEBUG_KMS("got esi %02x %02x %02x\n", esi[0], esi[1], esi[2]);
+			ret = drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, &handled);
+
+			if (handled) {
+				mutex_lock(&intel_dp->mst_mgr.aux_lock);
+				for (retry = 0; retry < 3; retry++) {
+					int wret;
+					wret = drm_dp_dpcd_write(&intel_dp->aux,
+								 DP_SINK_COUNT_ESI+1,
+								 &esi[1], 3);
+					if (wret == 3) {
+						break;
+					}
+				}
+				mutex_unlock(&intel_dp->mst_mgr.aux_lock);
+
+				mutex_lock(&intel_dp->mst_mgr.aux_lock);
+				bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
+				mutex_unlock(&intel_dp->mst_mgr.aux_lock);
+				if (bret == true) {
+					DRM_DEBUG_KMS("got esi2 %02x %02x %02x\n", esi[0], esi[1], esi[2]);
+					goto go_again;
+				}
+			} else
+				ret = 0;
+
+			return ret;
+		} else {
+			struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+			DRM_DEBUG_KMS("failed to get ESI - device may have failed\n");
+			intel_dp->is_mst = false;
+			drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
+			/* send a hotplug event */
+			drm_kms_helper_hotplug_event(intel_dig_port->base.base.dev);
+		}
+	}
+	return -EINVAL;
+}
 
 void
 intel_dp_check_link_status(struct intel_dp *intel_dp)
@@ -3163,6 +3267,7 @@ intel_dp_detect(struct drm_connector *connector, bool force)
 	enum drm_connector_status status;
 	enum intel_display_power_domain power_domain;
 	struct edid *edid = NULL;
+	bool ret;
 
 	intel_runtime_pm_get(dev_priv);
 
@@ -3172,6 +3277,12 @@ intel_dp_detect(struct drm_connector *connector, bool force)
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, drm_get_connector_name(connector));
 
+	if (intel_dp->is_mst) {
+		/* MST devices are disconnected from a monitor POV */
+		status = connector_status_disconnected;
+		goto out;
+	}
+
 	intel_dp->has_audio = false;
 
 	if (HAS_PCH_SPLIT(dev))
@@ -3184,6 +3295,16 @@ intel_dp_detect(struct drm_connector *connector, bool force)
 
 	intel_dp_probe_oui(intel_dp);
 
+	ret = intel_dp_probe_mst(intel_dp);
+	if (ret) {
+		/* if we are in MST mode then this connector
+		   won't appear connected or have anything with EDID on it */
+		if (intel_encoder->type != INTEL_OUTPUT_EDP)
+			intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
+		status = connector_status_disconnected;
+		goto out;
+	}
+
 	if (intel_dp->force_audio != HDMI_AUDIO_AUTO) {
 		intel_dp->has_audio = (intel_dp->force_audio == HDMI_AUDIO_ON);
 	} else {
@@ -3379,6 +3500,7 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 
 	drm_dp_aux_unregister_i2c_bus(&intel_dp->aux);
+	intel_dp_mst_encoder_cleanup(intel_dig_port);
 	drm_encoder_cleanup(encoder);
 	if (is_edp(intel_dp)) {
 		cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
@@ -3463,7 +3585,7 @@ bool intel_dp_is_edp(struct drm_device *dev, enum port port)
 	return false;
 }
 
-static void
+void
 intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector)
 {
 	struct intel_connector *intel_connector = to_intel_connector(connector);
@@ -3959,6 +4081,13 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 
 	intel_dp->psr_setup_done = false;
 
+	/* init MST on ports that can support it */
+	if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
+		if (port == PORT_B || port == PORT_C || port == PORT_D) {
+			intel_dp_mst_encoder_init(intel_dig_port, intel_connector->base.base.id);
+		}
+	}
+
 	if (!intel_edp_init_connector(intel_dp, intel_connector, &power_seq)) {
 		drm_dp_aux_unregister_i2c_bus(&intel_dp->aux);
 		if (is_edp(intel_dp)) {
@@ -3989,6 +4118,7 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 void
 intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_digital_port *intel_dig_port;
 	struct intel_encoder *intel_encoder;
 	struct drm_encoder *encoder;
@@ -4029,6 +4159,10 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 	intel_dig_port->port = port;
 	intel_dig_port->dp.output_reg = output_reg;
 
+	/* for now only use new IRQ handling for MST capable ports */
+	if (intel_dig_port->dp.can_mst)
+		dev_priv->hpd_irq_port[port] = intel_dig_port;
+
 	intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
 	intel_encoder->crtc_mask = (1 << 0) | (1 << 1) | (1 << 2);
 	intel_encoder->cloneable = 0;
@@ -4040,3 +4174,93 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 		kfree(intel_connector);
 	}
 }
+
+/*
+ * Handle DP IRQ close to spec recommendations
+ * Use hw to detect long vs short pulses
+ *
+ * If we get a long pulse - we need to read DPCD first
+ * If we get a short pulse - we need to check link irq/status
+ * returning 1 causes the old detect to happen for HDMI
+ */
+int intel_dp_handle_hpd_irq(struct intel_digital_port *intel_dig_port,
+			    bool hpd_long)
+{
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	int ret;
+
+	if (!intel_dp->output_reg)
+		return 1;
+
+	DRM_DEBUG_KMS("got hpd irq on port %d - %s\n", intel_dig_port->port,
+		      hpd_long ? "long" : "short");
+	/* we have to re-read DPCD only on a long irq */
+	if (hpd_long) {
+		if (!intel_dp_get_dpcd(intel_dp))
+			goto mst_fail;
+
+		intel_dp_probe_oui(intel_dp);
+
+		if (!intel_dp_probe_mst(intel_dp))
+			goto mst_fail;
+	}
+
+	if (intel_dp->is_mst) {
+		ret = intel_dp_check_mst_status(intel_dp);
+		if (ret == -EINVAL)
+			return 1;
+	} else {
+		intel_dp_check_link_status(intel_dp);
+		return 1;
+	}
+
+	return 0;
+
+mst_fail:
+	/* if we were in MST mode, and device is not there get out of MST mode */
+	if (intel_dp->is_mst) {
+		DRM_DEBUG_KMS("failed to get ESI - device may have failed %d vs %d\n", intel_dp->is_mst, intel_dp->mst_mgr.mst_state);
+		intel_dp->is_mst = false;
+		drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
+		drm_kms_helper_hotplug_event(dev);
+	}
+	return 1;
+}
+
+void intel_dp_mst_suspend(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	/* disable MST */
+	for (i = 0; i < I915_MAX_PORTS; i++) {
+		struct intel_digital_port *intel_dig_port = dev_priv->hpd_irq_port[i];
+		if (!intel_dig_port)
+			continue;
+
+		if (intel_dig_port->base.type == INTEL_OUTPUT_DISPLAYPORT) {
+			if (intel_dig_port->dp.is_mst)
+				drm_dp_mst_topology_mgr_suspend(&intel_dig_port->dp.mst_mgr);
+		}
+	}
+}
+
+void intel_dp_mst_resume(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	for (i = 0; i < I915_MAX_PORTS; i++) {
+		struct intel_digital_port *intel_dig_port = dev_priv->hpd_irq_port[i];
+		if (!intel_dig_port)
+			continue;
+		if (intel_dig_port->base.type == INTEL_OUTPUT_DISPLAYPORT) {
+			int ret;
+			ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
+			if (ret != 0) {
+				intel_dp_check_mst_status(&intel_dig_port->dp);
+			}
+		}
+	}
+}
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
new file mode 100644
index 0000000..1fca5e4
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -0,0 +1,538 @@
+/*
+ * Copyright © 2008 Intel Corporation
+ *             2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <drm/drmP.h>
+#include "i915_drv.h"
+#include "intel_drv.h"
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+
+bool
+intel_dp_mst_compute_config(struct intel_encoder *encoder,
+			    struct intel_crtc_config *pipe_config)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = encoder->base.dev;
+	int bpp;
+	int lane_count, slots;
+	struct drm_display_mode *adjusted_mode = &pipe_config->adjusted_mode;
+	struct intel_connector *found = NULL, *intel_connector;
+	int mst_pbn;
+
+	pipe_config->dp_encoder_is_mst = true;
+	pipe_config->has_pch_encoder = false;
+	pipe_config->has_dp_encoder = true;
+	bpp = 24;
+	lane_count = 4;
+	intel_dp->link_bw = DP_LINK_BW_5_4;
+	intel_dp->lane_count = lane_count;
+
+	pipe_config->pipe_bpp = 24;
+	pipe_config->port_clock = drm_dp_bw_code_to_link_rate(intel_dp->link_bw);
+
+	list_for_each_entry(intel_connector, &dev->mode_config.connector_list, base.head) {
+		if (intel_connector->new_encoder == encoder) {
+			found = intel_connector;
+			break;
+		}
+	}
+
+	if (!found) {
+		DRM_ERROR("can't find connector\n");
+		return false;
+	}
+
+	mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->clock, bpp);
+
+	pipe_config->pbn = mst_pbn;
+	slots = drm_dp_find_vcpi_slots(&intel_dp->mst_mgr, mst_pbn);
+
+	intel_link_compute_m_n(bpp, lane_count,
+			       adjusted_mode->crtc_clock,
+			       pipe_config->port_clock,
+			       &pipe_config->dp_m_n);
+
+	pipe_config->dp_m_n.tu = slots;
+	return true;
+
+}
+
+static void intel_dp_mst_mode_set(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+
+	intel_ddi_mode_set_dp(&intel_dig_port->base);
+}
+
+static void intel_mst_disable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	int ret;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, intel_mst->port);
+
+	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+	if (ret) {
+		DRM_ERROR("failed to update payload %d\n", ret);
+	}
+}
+
+static void intel_mst_post_disable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	/* this can fail */
+	drm_dp_check_act_status(&intel_dp->mst_mgr);
+	/* and this can also fail */
+	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+
+	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, intel_mst->port);
+
+	intel_dp->active_mst_links--;
+	intel_mst->port = NULL;
+	if (intel_dp->active_mst_links == 0) {
+		intel_dig_port->base.post_disable(&intel_dig_port->base);
+		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
+	}
+}
+
+static void intel_mst_pre_enable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port = intel_dig_port->port;
+	int ret;
+	uint32_t temp;
+	struct intel_connector *found = NULL, *intel_connector;
+	int slots;
+	struct drm_crtc *crtc = encoder->base.crtc;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	list_for_each_entry(intel_connector, &dev->mode_config.connector_list, base.head) {
+		if (intel_connector->new_encoder == encoder) {
+			found = intel_connector;
+			break;
+		}
+	}
+
+	if (!found) {
+		DRM_ERROR("can't find connector\n");
+		return;
+	}
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+	intel_mst->port = found->port;
+
+	if (intel_dp->active_mst_links == 0) {
+		enum port port = intel_ddi_get_encoder_port(encoder);
+
+		I915_WRITE(PORT_CLK_SEL(port), intel_crtc->ddi_pll_sel);
+
+		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
+
+
+		intel_dp_start_link_train(intel_dp);
+		intel_dp_complete_link_train(intel_dp);
+		intel_dp_stop_link_train(intel_dp);
+	}
+
+	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
+				       intel_mst->port, intel_crtc->config.pbn, &slots);
+	if (ret == false) {
+		DRM_ERROR("failed to allocate vcpi\n");
+		return;
+	}
+
+
+	intel_dp->active_mst_links++;
+	temp = I915_READ(DP_TP_STATUS(port));
+	I915_WRITE(DP_TP_STATUS(port), temp);
+
+	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+}
+
+static void intel_mst_enable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port = intel_dig_port->port;
+	int ret;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	if (wait_for((I915_READ(DP_TP_STATUS(port)) & DP_TP_STATUS_ACT_SENT),
+		     1))
+		DRM_ERROR("Timed out waiting for ACT sent\n");
+
+	ret = drm_dp_check_act_status(&intel_dp->mst_mgr);
+
+	ret = drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+}
+
+static bool intel_dp_mst_enc_get_hw_state(struct intel_encoder *encoder,
+				      enum pipe *pipe)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	*pipe = intel_mst->pipe;
+	if (intel_mst->port)
+		return true;
+	return false;
+}
+
+static void intel_dp_mst_enc_get_config(struct intel_encoder *encoder,
+					struct intel_crtc_config *pipe_config)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum transcoder cpu_transcoder = crtc->config.cpu_transcoder;
+	u32 temp, flags = 0;
+
+	pipe_config->has_dp_encoder = true;
+
+	temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+	if (temp & TRANS_DDI_PHSYNC)
+		flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		flags |= DRM_MODE_FLAG_NHSYNC;
+	if (temp & TRANS_DDI_PVSYNC)
+		flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		flags |= DRM_MODE_FLAG_NVSYNC;
+
+	switch (temp & TRANS_DDI_BPC_MASK) {
+	case TRANS_DDI_BPC_6:
+		pipe_config->pipe_bpp = 18;
+		break;
+	case TRANS_DDI_BPC_8:
+		pipe_config->pipe_bpp = 24;
+		break;
+	case TRANS_DDI_BPC_10:
+		pipe_config->pipe_bpp = 30;
+		break;
+	case TRANS_DDI_BPC_12:
+		pipe_config->pipe_bpp = 36;
+		break;
+	default:
+		break;
+	}
+	pipe_config->adjusted_mode.flags |= flags;
+	intel_dp_get_m_n(crtc, pipe_config);
+
+	intel_ddi_clock_get(&intel_dig_port->base, pipe_config);
+}
+
+static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+	struct edid *edid;
+	int ret;
+
+	edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
+	if (!edid)
+		return 0;
+
+	ret = intel_connector_update_modes(connector, edid);
+	kfree(edid);
+
+	return ret;
+}
+
+static enum drm_connector_status
+intel_mst_port_dp_detect(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+
+	return drm_dp_mst_detect_port(&intel_dp->mst_mgr, intel_connector->port);
+}
+
+static enum drm_connector_status
+intel_dp_mst_detect(struct drm_connector *connector, bool force)
+{
+	enum drm_connector_status status;
+	status = intel_mst_port_dp_detect(connector);
+	return status;
+}
+
+static int
+intel_dp_mst_set_property(struct drm_connector *connector,
+			  struct drm_property *property,
+			  uint64_t val)
+{
+	return 0;
+}
+
+static void
+intel_dp_mst_connector_destroy(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+
+	if (!IS_ERR_OR_NULL(intel_connector->edid))
+		kfree(intel_connector->edid);
+
+	drm_connector_cleanup(connector);
+	kfree(connector);
+}
+
+static const struct drm_connector_funcs intel_dp_mst_connector_funcs = {
+	.dpms = intel_connector_dpms,
+	.detect = intel_dp_mst_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.set_property = intel_dp_mst_set_property,
+	.destroy = intel_dp_mst_connector_destroy,
+};
+
+static int intel_dp_mst_get_modes(struct drm_connector *connector)
+{
+	return intel_dp_mst_get_ddc_modes(connector);
+}
+
+static enum drm_mode_status
+intel_dp_mst_mode_valid(struct drm_connector *connector,
+			struct drm_display_mode *mode)
+{
+	/* TODO - validate mode against available PBN for link */
+	if (mode->clock < 10000)
+		return MODE_CLOCK_LOW;
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		return MODE_H_ILLEGAL;
+
+	return MODE_OK;
+}
+
+struct drm_encoder *intel_mst_best_encoder(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+	return &intel_dp->mst_encoders[0]->base.base;
+}
+
+static const struct drm_connector_helper_funcs intel_dp_mst_connector_helper_funcs = {
+	.get_modes = intel_dp_mst_get_modes,
+	.mode_valid = intel_dp_mst_mode_valid,
+	.best_encoder = intel_mst_best_encoder,
+};
+
+void intel_dp_mst_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(encoder);
+
+	drm_encoder_cleanup(encoder);
+	kfree(intel_mst);
+}
+
+static const struct drm_encoder_funcs intel_dp_mst_enc_funcs = {
+	.destroy = intel_dp_mst_encoder_destroy,
+};
+
+static bool intel_dp_mst_get_hw_state(struct intel_connector *connector)
+{
+	if (connector->encoder) {
+		enum pipe pipe;
+		if (!connector->encoder->get_hw_state(connector->encoder, &pipe))
+			return false;
+		return true;
+	}
+	return false;
+}
+
+static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *pathprop)
+{
+	struct intel_dp *intel_dp = container_of(mgr, struct intel_dp, mst_mgr);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_connector *intel_connector;
+	struct drm_connector *connector;
+	int i;
+
+	intel_connector = kzalloc(sizeof(*intel_connector), GFP_KERNEL);
+	if (!intel_connector)
+		return NULL;
+
+	connector = &intel_connector->base;
+	drm_connector_init(dev, connector, &intel_dp_mst_connector_funcs, DRM_MODE_CONNECTOR_DisplayPort);
+	drm_connector_helper_add(connector, &intel_dp_mst_connector_helper_funcs);
+
+	intel_connector->unregister = intel_connector_unregister;
+	intel_connector->get_hw_state = intel_dp_mst_get_hw_state;
+	intel_connector->mst_port = intel_dp;
+	intel_connector->port = port;
+
+	for (i = PIPE_A; i <= PIPE_C; i++) {
+		drm_mode_connector_attach_encoder(&intel_connector->base,
+						  &intel_dp->mst_encoders[i]->base.base);
+	}
+	intel_dp_add_properties(intel_dp, connector);
+
+	drm_object_attach_property(&connector->base, dev->mode_config.path_property, 0);
+	drm_mode_connector_set_path_property(connector, pathprop);
+	drm_reinit_primary_mode_group(dev);
+	mutex_lock(&dev->mode_config.mutex);
+	drm_fb_helper_add_one_connector(&dev_priv->fbdev->helper, connector);
+	mutex_unlock(&dev->mode_config.mutex);
+	drm_sysfs_connector_add(&intel_connector->base);
+	return connector;
+}
+
+static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
+					   struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct drm_device *dev = connector->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	/* need to nuke the connector */
+	mutex_lock(&dev->mode_config.mutex);
+	intel_connector_dpms(connector, DRM_MODE_DPMS_OFF);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	intel_connector->unregister(intel_connector);
+
+	mutex_lock(&dev->mode_config.mutex);
+	drm_fb_helper_remove_one_connector(&dev_priv->fbdev->helper, connector);
+	drm_connector_cleanup(connector);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	drm_reinit_primary_mode_group(dev);
+
+	kfree(intel_connector);
+	DRM_DEBUG_KMS("\n");
+}
+
+static void intel_dp_mst_hotplug(struct drm_dp_mst_topology_mgr *mgr)
+{
+	struct intel_dp *intel_dp = container_of(mgr, struct intel_dp, mst_mgr);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+
+	drm_kms_helper_hotplug_event(dev);
+}
+
+struct drm_dp_mst_topology_cbs mst_cbs = {
+	.add_connector = intel_dp_add_mst_connector,
+	.destroy_connector = intel_dp_destroy_mst_connector,
+	.hotplug = intel_dp_mst_hotplug,
+};
+
+static struct intel_dp_mst_encoder *
+intel_dp_create_fake_mst_encoder(struct intel_digital_port *intel_dig_port, enum pipe pipe)
+{
+	struct intel_dp_mst_encoder *intel_mst;
+	struct intel_encoder *intel_encoder;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+
+	intel_mst = kzalloc(sizeof(*intel_mst), GFP_KERNEL);
+
+	if (!intel_mst)
+		return NULL;
+
+	intel_mst->pipe = pipe;
+	intel_encoder = &intel_mst->base;
+	intel_mst->primary = intel_dig_port;
+
+	drm_encoder_init(dev, &intel_encoder->base, &intel_dp_mst_enc_funcs,
+			 DRM_MODE_ENCODER_DPMST);
+
+	intel_encoder->type = INTEL_OUTPUT_DP_MST;
+	intel_encoder->crtc_mask = 0x7;
+	intel_encoder->cloneable = 0;
+
+	intel_encoder->compute_config = intel_dp_mst_compute_config;
+	intel_encoder->mode_set = intel_dp_mst_mode_set;
+	intel_encoder->disable = intel_mst_disable_dp;
+	intel_encoder->post_disable = intel_mst_post_disable_dp;
+	intel_encoder->pre_enable = intel_mst_pre_enable_dp;
+	intel_encoder->enable = intel_mst_enable_dp;
+	intel_encoder->get_hw_state = intel_dp_mst_enc_get_hw_state;
+	intel_encoder->get_config = intel_dp_mst_enc_get_config;
+
+	return intel_mst;
+
+}
+
+static bool
+intel_dp_create_fake_mst_encoders(struct intel_digital_port *intel_dig_port)
+{
+	int i;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	for (i = PIPE_A; i <= PIPE_C; i++)
+		intel_dp->mst_encoders[i] = intel_dp_create_fake_mst_encoder(intel_dig_port, i);
+	return true;
+}
+
+int
+intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_base_id)
+{
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	int ret;
+
+	intel_dp->can_mst = true;
+	intel_dp->mst_mgr.cbs = &mst_cbs;
+
+	/* create encoders */
+	intel_dp_create_fake_mst_encoders(intel_dig_port);
+	ret = drm_dp_mst_topology_mgr_init(&intel_dp->mst_mgr, dev->dev, &intel_dp->aux, 16, 3, conn_base_id);
+	if (ret) {
+		intel_dp->can_mst = false;
+		return ret;
+	}
+	return 0;
+}
+
+void
+intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port)
+{
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	if (!intel_dp->can_mst)
+		return;
+
+	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
+	/* encoders will get killed by normal cleanup */
+}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 8e41cdc..e7fcd6c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -32,7 +32,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
-#include <drm/drm_dp_helper.h>
+#include <drm/drm_dp_mst_helper.h>
 
 /**
  * _wait_for - magic (register) wait macro
@@ -100,6 +100,7 @@
 #define INTEL_OUTPUT_EDP 8
 #define INTEL_OUTPUT_DSI 9
 #define INTEL_OUTPUT_UNKNOWN 10
+#define INTEL_OUTPUT_DP_MST 11
 
 #define INTEL_DVO_CHIP_NONE 0
 #define INTEL_DVO_CHIP_LVDS 1
@@ -207,6 +208,10 @@ struct intel_connector {
 	/* since POLL and HPD connectors may use the same HPD line keep the native
 	   state of connector->polled in case hotplug storm detection changes it */
 	u8 polled;
+
+	void *port; /* store this opaque as its illegal to dereference it */
+
+	struct intel_dp *mst_port;
 };
 
 typedef struct dpll {
@@ -340,6 +345,9 @@ struct intel_crtc_config {
 	bool ips_enabled;
 
 	bool double_wide;
+
+	bool dp_encoder_is_mst;
+	int pbn;
 };
 
 struct intel_pipe_wm {
@@ -487,6 +495,7 @@ struct intel_hdmi {
 			       struct drm_display_mode *adjusted_mode);
 };
 
+struct intel_dp_mst_encoder;
 #define DP_MAX_DOWNSTREAM_PORTS		0x10
 
 /**
@@ -527,8 +536,17 @@ struct intel_dp {
 	unsigned long last_backlight_off;
 	bool psr_setup_done;
 	bool use_tps3;
+	bool can_mst; /* this port supports mst */
+	bool is_mst;
+	int active_mst_links;
+	/* connector directly attached - won't be use for modeset in mst world */
 	struct intel_connector *attached_connector;
 
+	/* mst connector list */
+	struct intel_connector *mst_connectors;
+	struct intel_dp_mst_encoder *mst_encoders[I915_MAX_PIPES];
+	struct drm_dp_mst_topology_mgr mst_mgr;
+
 	uint32_t (*get_aux_clock_divider)(struct intel_dp *dp, int index);
 	/*
 	 * This function returns the value we have to program the AUX_CTL
@@ -554,6 +572,13 @@ struct intel_digital_port {
 	struct intel_hdmi hdmi;
 };
 
+struct intel_dp_mst_encoder {
+	struct intel_encoder base;
+	enum pipe pipe;
+	struct intel_digital_port *primary;
+	void *port; /* store this opaque as its illegal to dereference it */
+};
+
 static inline int
 vlv_dport_to_channel(struct intel_digital_port *dport)
 {
@@ -621,6 +646,12 @@ enc_to_dig_port(struct drm_encoder *encoder)
 	return container_of(encoder, struct intel_digital_port, base.base);
 }
 
+static inline struct intel_dp_mst_encoder *
+enc_to_mst(struct drm_encoder *encoder)
+{
+	return container_of(encoder, struct intel_dp_mst_encoder, base.base);
+}
+
 static inline struct intel_dp *enc_to_intel_dp(struct drm_encoder *encoder)
 {
 	return &enc_to_dig_port(encoder)->dp;
@@ -684,6 +715,10 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_config *pipe_config);
 
 void intel_ddi_mode_set_dp(struct intel_encoder *encoder);
+void intel_ddi_clock_get(struct intel_encoder *encoder,
+			 struct intel_crtc_config *pipe_config);
+void intel_ddi_force_act(struct intel_encoder *encoder, bool state);
+void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state);
 
 /* intel_display.c */
 const char *intel_output_name(int output);
@@ -800,6 +835,14 @@ void intel_edp_psr_disable(struct intel_dp *intel_dp);
 void intel_edp_psr_update(struct drm_device *dev);
 void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate);
 
+int intel_dp_handle_hpd_irq(struct intel_digital_port *digport, bool long_hpd);
+void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector);
+void intel_dp_mst_suspend(struct drm_device *dev);
+void intel_dp_mst_resume(struct drm_device *dev);
+
+/* intel_dp_mst.c */
+int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
+void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
 /* intel_dsi.c */
 bool intel_dsi_init(struct drm_device *dev);
 
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index fce4a0d..74caeba 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -349,6 +349,11 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		}
 
 		encoder = connector->encoder;
+		if (!encoder) {
+			struct drm_connector_helper_funcs *connector_funcs;
+			connector_funcs = connector->helper_private;
+			encoder = connector_funcs->best_encoder(connector);
+		}
 		if (!encoder || WARN_ON(!encoder->crtc)) {
 			DRM_DEBUG_KMS("connector %d has no encoder or crtc, skipping\n",
 				      connector->base.id);
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index acde294..bce66b2 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -352,6 +352,7 @@ int intel_opregion_notify_encoder(struct intel_encoder *intel_encoder,
 	case INTEL_OUTPUT_UNKNOWN:
 	case INTEL_OUTPUT_DISPLAYPORT:
 	case INTEL_OUTPUT_HDMI:
+	case INTEL_OUTPUT_DP_MST:
 		type = DISPLAY_TYPE_EXTERNAL_FLAT_PANEL;
 		break;
 	case INTEL_OUTPUT_EDP:
-- 
1.9.0

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH 11/11] i915: mst topology dumper in debugfs (v0.2)

[Dave Airlie]

From: Dave Airlie <airlied@redhat.com>

use the mst helper code to dump the topology in debugfs.

v0.2: drop is_mst check - as we want to dump other info

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 88e944f..2d455ed 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2378,6 +2378,28 @@ struct pipe_crc_info {
 	enum pipe pipe;
 };
 
+static int i915_dp_mst_info(struct seq_file *m, void *unused)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_encoder *encoder;
+	struct intel_encoder *intel_encoder;
+	struct intel_digital_port *intel_dig_port;
+	drm_modeset_lock_all(dev);
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+		intel_encoder = to_intel_encoder(encoder);
+		if (intel_encoder->type != INTEL_OUTPUT_DISPLAYPORT)
+			continue;
+		intel_dig_port = enc_to_dig_port(encoder);
+		if (!intel_dig_port->dp.can_mst)
+			continue;
+
+		drm_dp_mst_dump_topology(m, &intel_dig_port->dp.mst_mgr);
+	}
+	drm_modeset_unlock_all(dev);
+	return 0;
+}
+
 static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
 {
 	struct pipe_crc_info *info = inode->i_private;
@@ -3813,6 +3835,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
 	{"i915_pc8_status", i915_pc8_status, 0},
 	{"i915_power_domain_info", i915_power_domain_info, 0},
 	{"i915_display_info", i915_display_info, 0},
+	{"i915_dp_mst_info", i915_dp_mst_info, 0},
 };
 #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
 
-- 
1.9.0