Re: [PATCH v2 4/4] drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, May 04, 2016 at 03:54:41PM +0530, Sharma, Shashank wrote:
> 
> 
> On 5/3/2016 12:38 AM, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > DP dual mode type 1 DVI adaptors aren't required to implement any
> > registers, so it's a bit hard to detect them. The best way would
> > be to check the state of the CONFIG1 pin, but we have no way to
> > do that. So as a last resort, check the VBT to see if the HDMI
> > port is in fact a dual mode capable DP port.
> >
> > v2: Deal with VBT code reorganization
> >      Deal with DRM_DP_DUAL_MODE_UNKNOWN
> >      Reduce DEVICE_TYPE_DP_DUAL_MODE_BITS a bit
> >      Accept both DP and HDMI dvo_port in VBT as my BSW
> >      at least declare its DP port as HDMI :(
> >
> > Cc: stable@vger.kernel.org
> > Cc: Tore Anderson <tore@fud.no>
> > Reported-by: Tore Anderson <tore@fud.no>
> > Fixes: 7a0baa623446 ("Revert "drm/i915: Disable 12bpc hdmi for now"")
> > Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > Cc: Shashank Sharma <shashank.sharma@intel.com>
> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >   drivers/gpu/drm/i915/i915_drv.h       |  1 +
> >   drivers/gpu/drm/i915/intel_bios.c     | 36 +++++++++++++++++++++++++++++++++++
> >   drivers/gpu/drm/i915/intel_hdmi.c     | 30 +++++++++++++++++++++++++----
> >   drivers/gpu/drm/i915/intel_vbt_defs.h | 13 +++++++++++++
> >   4 files changed, 76 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index ff6aaf0c4e1e..abe43922a08f 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -3489,6 +3489,7 @@ bool intel_bios_is_valid_vbt(const void *buf, size_t size);
> >   bool intel_bios_is_tv_present(struct drm_i915_private *dev_priv);
> >   bool intel_bios_is_lvds_present(struct drm_i915_private *dev_priv, u8 *i2c_pin);
> >   bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
> > +bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port);
> >   bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv, enum port *port);
> >   bool intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
> >   				     enum port port);
> > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> > index 81518116e00d..8b68c4882fba 100644
> > --- a/drivers/gpu/drm/i915/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/intel_bios.c
> > @@ -1597,6 +1597,42 @@ bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port)
> >   	return false;
> >   }
> >
> > +bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port)
> > +{
> > +	static const struct {
> > +		u16 dp, hdmi;
> > +	} port_mapping[] = {
> > +		/*
> > +		 * Buggy VBTs may declare DP ports as having
> > +		 * HDMI type dvo_port :( So let's check both.
> > +		 */
> > +		[PORT_B] = { DVO_PORT_DPB, DVO_PORT_HDMIB, },
> > +		[PORT_C] = { DVO_PORT_DPC, DVO_PORT_HDMIC, },
> > +		[PORT_D] = { DVO_PORT_DPD, DVO_PORT_HDMID, },
> > +		[PORT_E] = { DVO_PORT_DPE, DVO_PORT_HDMIE, },
> > +	};
> > +	int i;
> > +
> > +	if (port == PORT_A || port >= ARRAY_SIZE(port_mapping))
> > +		return false;
> > +
> > +	if (!dev_priv->vbt.child_dev_num)
> > +		return false;
> > +
> > +	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
> > +		const union child_device_config *p_child =
> > +			&dev_priv->vbt.child_dev[i];
> > +
> > +		if ((p_child->common.dvo_port == port_mapping[port].dp ||
> > +		     p_child->common.dvo_port == port_mapping[port].hdmi) &&
> > +		    (p_child->common.device_type & DEVICE_TYPE_DP_DUAL_MODE_BITS) ==
> > +		    (DEVICE_TYPE_DP_DUAL_MODE & DEVICE_TYPE_DP_DUAL_MODE_BITS))
> > +			return true;
> > +	}
> > +
> > +	return false;
> > +}
> > +
> >   /**
> >    * intel_bios_is_dsi_present - is DSI present in VBT
> >    * @dev_priv:	i915 device instance
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > index c4d93e6b4bed..6b52c6accf6a 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -1396,16 +1396,38 @@ intel_hdmi_unset_edid(struct drm_connector *connector)
> >   }
> >
> >   static void
> > -intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector)
> > +intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
> >   {
> >   	struct drm_i915_private *dev_priv = to_i915(connector->dev);
> >   	struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
> > +	enum port port = hdmi_to_dig_port(hdmi)->port;
> >   	struct i2c_adapter *adapter =
> >   		intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
> >   	enum drm_dp_dual_mode_type type = drm_dp_dual_mode_detect(adapter);
> >
> > -	if (type == DRM_DP_DUAL_MODE_NONE ||
> > -	    type == DRM_DP_DUAL_MODE_UNKNOWN)
> > +	/*
> > +	 * Type 1 DVI adaptors are not required to implement any
> > +	 * registers, so we can't always detect their presence.
> > +	 * Ideally we should be able to check the state of the
> > +	 * CONFIG1 pin, but no such luck on our hardware.
> > +	 *
> > +	 * The only method left to us is to check the VBT to see
> > +	 * if the port is a dual mode capable DP port. But let's
> > +	 * only do that when we sucesfully read the EDID, to avoid
> > +	 * confusing log messages about DP dual mode adaptors when
> > +	 * there's nothing connected to the port.
> > +	 */
> > +	if (type == DRM_DP_DUAL_MODE_UNKNOWN) {
> > +		if (has_edid &&
> > +		    intel_bios_is_port_dp_dual_mode(dev_priv, port)) {
> > +			DRM_DEBUG_KMS("Assuming DP dual mode adaptor presence based on VBT\n");
> > +			type = DRM_DP_DUAL_MODE_TYPE1_DVI;
> > +		} else {
> > +			type = DRM_DP_DUAL_MODE_NONE;
> > +		}
> > +	}
> > +
> > +	if (type == DRM_DP_DUAL_MODE_NONE)
> >   		return;
> >
> >   	hdmi->dp_dual_mode.type = type;
> > @@ -1432,7 +1454,7 @@ intel_hdmi_set_edid(struct drm_connector *connector, bool force)
> >   				    intel_gmbus_get_adapter(dev_priv,
> >   				    intel_hdmi->ddc_bus));
> >
> > -		intel_hdmi_dp_dual_mode_detect(connector);
> > +		intel_hdmi_dp_dual_mode_detect(connector, edid != NULL);
> >
> >   		intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
> >   	}
> > diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h
> > index a4a42f254c35..b1019e01e51d 100644
> > --- a/drivers/gpu/drm/i915/intel_vbt_defs.h
> > +++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
> > @@ -746,6 +746,7 @@ struct bdb_psr {
> >   #define	 DEVICE_TYPE_INT_TV	0x1009
> >   #define	 DEVICE_TYPE_HDMI	0x60D2
> >   #define	 DEVICE_TYPE_DP		0x68C6
> > +#define	 DEVICE_TYPE_DP_DUAL_MODE	0x60D6
> >   #define	 DEVICE_TYPE_eDP	0x78C6
> >
> >   #define  DEVICE_TYPE_CLASS_EXTENSION	(1 << 15)
> > @@ -780,6 +781,18 @@ struct bdb_psr {
> >   	 DEVICE_TYPE_DISPLAYPORT_OUTPUT | \
> >   	 DEVICE_TYPE_ANALOG_OUTPUT)
> >
> > +#define DEVICE_TYPE_DP_DUAL_MODE_BITS \
> > +	(DEVICE_TYPE_INTERNAL_CONNECTOR | \
> > +	 DEVICE_TYPE_NOT_HDMI_OUTPUT | \
> Why do we need this one ? Shouldn't the others cover all the cases ?
> Is there a special case in your mind ?

Doh. That bit shouldn't be here. It's the only bit I was ignoring in
the previous version, and definitely we should ignore it still. I'll
send out a v3. Good catch there.

> 
> Regards
> Shashank
> > +	 DEVICE_TYPE_MIPI_OUTPUT | \
> > +	 DEVICE_TYPE_COMPOSITE_OUTPUT | \
> > +	 DEVICE_TYPE_LVDS_SINGALING | \
> > +	 DEVICE_TYPE_TMDS_DVI_SIGNALING | \
> > +	 DEVICE_TYPE_VIDEO_SIGNALING | \
> > +	 DEVICE_TYPE_DISPLAYPORT_OUTPUT | \
> > +	 DEVICE_TYPE_DIGITAL_OUTPUT | \
> > +	 DEVICE_TYPE_ANALOG_OUTPUT)
> > +
> >   /* define the DVO port for HDMI output type */
> >   #define		DVO_B		1
> >   #define		DVO_C		2
> >

-- 
Ville Syrjälä
Intel OTC