* [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
@ 2017-02-02 10:12 Takashi Iwai
2017-02-03 13:32 ` Takashi Iwai
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Iwai @ 2017-02-02 10:12 UTC (permalink / raw)
To: alsa-devel, ntel-gfx
Cc: Pierre-Louis Bossart, Jani Nikula, rakesh.a.ughreja, Jerome Anand,
Daniel Vetter, Ville Syrjälä
The audio chicken bit (register offset 0x62f38) seems required to make
DP audio working on some machines. At least, on Dell Wyse 3040, I
failed to get the audio unless this bit is set once.
Strangely, the bit seems necessary only once, and it persists after
that, even some power-off cycles. The register is supposedly
write-only, so it's no evidence whether the bit keeps effect
persistently. But, judging from the experiment, it looks enough to
set it up once at the device initialization.
The patch is basically a cut from the original patch by Pierre-Louis
Bossart.
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_reg.h | 3 +++
drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4e24ba0cdbe8..4f15a3dc6d98 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2062,6 +2062,9 @@ enum skl_disp_power_wells {
#define I915_HDMI_LPE_AUDIO_SIZE 0x1000
/* DisplayPort Audio w/ LPE */
+#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38)
+#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0)
+
#define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20)
#define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30)
#define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34)
diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
index d3ffe0012692..3ba2799e93bd 100644
--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
+++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
@@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
goto err_free_irq;
}
+ /* enable chicken bit; at least this is required for Dell Wyse 3040
+ * with DP outputs (but only sometimes by some reason!)
+ */
+ I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
+ I915_READ(VLV_AUD_CHICKEN_BIT_REG) |
+ VLV_CHICKEN_BIT_DBG_ENABLE);
+
return 0;
err_free_irq:
irq_free_desc(dev_priv->lpe_audio.irq);
--
2.11.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
2017-02-02 10:12 [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Takashi Iwai
@ 2017-02-03 13:32 ` Takashi Iwai
2017-02-03 14:54 ` Ville Syrjälä
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Iwai @ 2017-02-03 13:32 UTC (permalink / raw)
To: intel-gfx; +Cc: alsa-devel, rakesh.a.ughreja
On Thu, 02 Feb 2017 11:12:53 +0100,
Takashi Iwai wrote:
>
> The audio chicken bit (register offset 0x62f38) seems required to make
> DP audio working on some machines. At least, on Dell Wyse 3040, I
> failed to get the audio unless this bit is set once.
>
> Strangely, the bit seems necessary only once, and it persists after
> that, even some power-off cycles. The register is supposedly
> write-only, so it's no evidence whether the bit keeps effect
> persistently. But, judging from the experiment, it looks enough to
> set it up once at the device initialization.
>
> The patch is basically a cut from the original patch by Pierre-Louis
> Bossart.
>
> Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
I gave a typo to intel-gfx ML address, now corrected, sorry.
Are you i915 guys OK with this change? I'd love to fix it for 4.11 in
time, so please check and give ACK.
thanks,
Takashi
> ---
> drivers/gpu/drm/i915/i915_reg.h | 3 +++
> drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 4e24ba0cdbe8..4f15a3dc6d98 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2062,6 +2062,9 @@ enum skl_disp_power_wells {
> #define I915_HDMI_LPE_AUDIO_SIZE 0x1000
>
> /* DisplayPort Audio w/ LPE */
> +#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38)
> +#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0)
> +
> #define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20)
> #define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30)
> #define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34)
> diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
> index d3ffe0012692..3ba2799e93bd 100644
> --- a/drivers/gpu/drm/i915/intel_lpe_audio.c
> +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
> @@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
> goto err_free_irq;
> }
>
> + /* enable chicken bit; at least this is required for Dell Wyse 3040
> + * with DP outputs (but only sometimes by some reason!)
> + */
> + I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
> + I915_READ(VLV_AUD_CHICKEN_BIT_REG) |
> + VLV_CHICKEN_BIT_DBG_ENABLE);
> +
> return 0;
> err_free_irq:
> irq_free_desc(dev_priv->lpe_audio.irq);
> --
> 2.11.0
>
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
2017-02-03 13:32 ` Takashi Iwai
@ 2017-02-03 14:54 ` Ville Syrjälä
2017-02-03 15:18 ` Takashi Iwai
0 siblings, 1 reply; 6+ messages in thread
From: Ville Syrjälä @ 2017-02-03 14:54 UTC (permalink / raw)
To: Takashi Iwai; +Cc: alsa-devel, intel-gfx, rakesh.a.ughreja
On Fri, Feb 03, 2017 at 02:32:37PM +0100, Takashi Iwai wrote:
> On Thu, 02 Feb 2017 11:12:53 +0100,
> Takashi Iwai wrote:
> >
> > The audio chicken bit (register offset 0x62f38) seems required to make
> > DP audio working on some machines. At least, on Dell Wyse 3040, I
> > failed to get the audio unless this bit is set once.
> >
> > Strangely, the bit seems necessary only once, and it persists after
> > that, even some power-off cycles. The register is supposedly
> > write-only, so it's no evidence whether the bit keeps effect
> > persistently. But, judging from the experiment, it looks enough to
> > set it up once at the device initialization.
> >
> > The patch is basically a cut from the original patch by Pierre-Louis
> > Bossart.
> >
> > Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
>
> I gave a typo to intel-gfx ML address, now corrected, sorry.
>
> Are you i915 guys OK with this change? I'd love to fix it for 4.11 in
> time, so please check and give ACK.
>
>
> thanks,
>
> Takashi
>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 3 +++
> > drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 4e24ba0cdbe8..4f15a3dc6d98 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -2062,6 +2062,9 @@ enum skl_disp_power_wells {
> > #define I915_HDMI_LPE_AUDIO_SIZE 0x1000
> >
> > /* DisplayPort Audio w/ LPE */
> > +#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38)
> > +#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0)
> > +
> > #define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20)
> > #define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30)
> > #define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34)
> > diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
> > index d3ffe0012692..3ba2799e93bd 100644
> > --- a/drivers/gpu/drm/i915/intel_lpe_audio.c
> > +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
> > @@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
> > goto err_free_irq;
> > }
> >
> > + /* enable chicken bit; at least this is required for Dell Wyse 3040
> > + * with DP outputs (but only sometimes by some reason!)
> > + */
> > + I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
> > + I915_READ(VLV_AUD_CHICKEN_BIT_REG) |
> > + VLV_CHICKEN_BIT_DBG_ENABLE);
RMW seems a little pointless since you verified that the register can't
actually be read.
So, with the read dropped
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > +
> > return 0;
> > err_free_irq:
> > irq_free_desc(dev_priv->lpe_audio.irq);
> > --
> > 2.11.0
> >
--
Ville Syrjälä
Intel OTC
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
2017-02-03 14:54 ` Ville Syrjälä
@ 2017-02-03 15:18 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-02-03 15:18 UTC (permalink / raw)
To: Ville Syrjälä; +Cc: alsa-devel, intel-gfx, rakesh.a.ughreja
On Fri, 03 Feb 2017 15:54:33 +0100,
Ville Syrjälä wrote:
>
> On Fri, Feb 03, 2017 at 02:32:37PM +0100, Takashi Iwai wrote:
> > On Thu, 02 Feb 2017 11:12:53 +0100,
> > Takashi Iwai wrote:
> > >
> > > The audio chicken bit (register offset 0x62f38) seems required to make
> > > DP audio working on some machines. At least, on Dell Wyse 3040, I
> > > failed to get the audio unless this bit is set once.
> > >
> > > Strangely, the bit seems necessary only once, and it persists after
> > > that, even some power-off cycles. The register is supposedly
> > > write-only, so it's no evidence whether the bit keeps effect
> > > persistently. But, judging from the experiment, it looks enough to
> > > set it up once at the device initialization.
> > >
> > > The patch is basically a cut from the original patch by Pierre-Louis
> > > Bossart.
> > >
> > > Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> > > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> >
> > I gave a typo to intel-gfx ML address, now corrected, sorry.
> >
> > Are you i915 guys OK with this change? I'd love to fix it for 4.11 in
> > time, so please check and give ACK.
> >
> >
> > thanks,
> >
> > Takashi
> >
> > > ---
> > > drivers/gpu/drm/i915/i915_reg.h | 3 +++
> > > drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++
> > > 2 files changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > index 4e24ba0cdbe8..4f15a3dc6d98 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -2062,6 +2062,9 @@ enum skl_disp_power_wells {
> > > #define I915_HDMI_LPE_AUDIO_SIZE 0x1000
> > >
> > > /* DisplayPort Audio w/ LPE */
> > > +#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38)
> > > +#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0)
> > > +
> > > #define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20)
> > > #define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30)
> > > #define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34)
> > > diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
> > > index d3ffe0012692..3ba2799e93bd 100644
> > > --- a/drivers/gpu/drm/i915/intel_lpe_audio.c
> > > +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
> > > @@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
> > > goto err_free_irq;
> > > }
> > >
> > > + /* enable chicken bit; at least this is required for Dell Wyse 3040
> > > + * with DP outputs (but only sometimes by some reason!)
> > > + */
> > > + I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
> > > + I915_READ(VLV_AUD_CHICKEN_BIT_REG) |
> > > + VLV_CHICKEN_BIT_DBG_ENABLE);
>
> RMW seems a little pointless since you verified that the register can't
> actually be read.
Indeed.
> So, with the read dropped
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Thanks!
Takashi
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 00/53] Intel LPE audio driver cleanups
@ 2017-02-02 17:02 Takashi Iwai
2017-02-02 17:02 ` [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Takashi Iwai
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Iwai @ 2017-02-02 17:02 UTC (permalink / raw)
To: alsa-devel; +Cc: Pierre-Louis Bossart, Jerome Anand
Hi,
this is a fairly largish patchset to fix and clean up Intel LPE audio
driver. Most of the patches are to clean up and refactoring of the
codes. As you can see in the diffstat below, quite lots of codes
(over 1600 lines) are reduced. Now the driver structure is flattened
to a single layer, and it looks much like a normal driver.
Besides the refactoring, there are a few major fixes: e.g. the fix for
the PCM disconnection that confuses PA,. the fix for the possible
sleep-in-atomic at hotplug, the fix for racy chmap accesses.
As new features, the driver supports the runtime PM properly now, it
sets the CA bit for DP, and it exposes the ELD via ALSA control
element.
The current code is available in topic/intel-lpe-audio-cleanup branch,
and it's based on the DP-audio branch, topic/intel-lpe-audio-dp that
I'm going to merge to for-next soon.
Takashi
===
Takashi Iwai (53):
ALSA: x86: Don't set PCM state to DISCONNECTED
ALSA: x86: Remove v1 ops and structs
ALSA: x86: Drop indirect calls of had_ops
ALSA: x86: Replace indirect register ops with direct calls
ALSA: x86: Replace indirect query_ops with direct calls
ALSA: x86: Drop snd_intel_had_interface indirect calls
ALSA: x86: Pass snd_intelhad object to helpers
ALSA: x86: Handle the error from hdmi_audio_probe() properly
ALSA: x86: Drop useless mutex at probe
ALSA: x86: Call event callback directly
ALSA: x86: Fix possible stale interrupt calls
ALSA: x86: Drop unused mid_hdmi_audio_is_busy()
ALSA: x86: Drop the global platform device reference
ALSA: x86: Drop global hlpe_state
ALSA: x86: Drop global ELD copy
ALSA: x86: Move the global underrun_count to struct snd_intelhad
ALSA: x86: Drop unused hw_silence field
ALSA: x86: Move dma_mask debug print into intel_hdmi_lpe_audio.c
ALSA: x86: Embed snd_intelhad into snd_card
ALSA: x86: Drop superfluous CHT PCI ID check
ALSA: x86: Check platform_data earlier
ALSA: x86: Call snd_card_register() at the end
ALSA: x86: Drop unused hdmi_audio_query()
ALSA: x86: Flatten two abstraction layers
ALSA: x86: Fold intel_hdmi_audio_if.c into main file
ALSA: x86: Replace pr_xxx() with dev_xxx()
ALSA: x86: Fix for CONFIG_PM=n
ALSA: x86: Remove indirect call of snd_pcm_period_elapsed()
ALSA: x86: Drop unused fields from snd_intelhad struct
ALSA: x86: Drop superfluous PCM private_free
ALSA: x86: Fix sleep-in-atomic via i915 notification
ALSA: x86: Remove superfluous check at resume
ALSA: x86: Drop had_get_hwstate()
ALSA: x86: Tidy up codes
ALSA: x86: Remove _v[12] suffices
ALSA: x86: Constfy tables
ALSA: x86: Remove superfluous irqsave flags
ALSA: x86: Fix racy access to chmap
ALSA: x86: Drop flag_underrun field
ALSA: x86: Drop superfluous state field
ALSA: x86: Drop redundant had_stream_pvt
ALSA: x86: Drop unused fields from pcm_stream_info
ALSA: x86: Properly manage PCM substream lifetype
ALSA: x86: Implement runtime PM
ALSA: x86: Move stream status into pcm_stream_info
ALSA: x86: Use the standard ELD bytes definitions
ALSA: x86: Reduce redundant register field names
ALSA: x86: Clean up unused defines and inclusions
ALSA: x86: Create ELD control element
ALSA: x86: Set CA bits for DisplayPort too
ALSA: x86: Simplify comments
ALSA: x86: Yet more tidy-up and clean-ups
ALSA: x86: Rename drv_status to connected
sound/x86/Makefile | 4 +-
sound/x86/intel_hdmi_audio.c | 1901 +++++++++++++++++++-------------------
sound/x86/intel_hdmi_audio.h | 117 +--
sound/x86/intel_hdmi_audio_if.c | 548 -----------
sound/x86/intel_hdmi_lpe_audio.c | 665 -------------
sound/x86/intel_hdmi_lpe_audio.h | 470 ++--------
6 files changed, 1026 insertions(+), 2679 deletions(-)
delete mode 100644 sound/x86/intel_hdmi_audio_if.c
delete mode 100644 sound/x86/intel_hdmi_lpe_audio.c
--
2.11.0
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
2017-02-02 17:02 [PATCH 00/53] Intel LPE audio driver cleanups Takashi Iwai
@ 2017-02-02 17:02 ` Takashi Iwai
2017-02-02 17:07 ` Takashi Iwai
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Iwai @ 2017-02-02 17:02 UTC (permalink / raw)
To: alsa-devel; +Cc: Pierre-Louis Bossart, Jerome Anand
The audio chicken bit (register offset 0x62f38) seems required to make
DP audio working on some machines. At least, on Dell Wyse 3040, I
failed to get the audio unless this bit is set once.
Strangely, the bit seems necessary only once, and it persists after
that, even some power-off cycles. The register is supposedly
write-only, so it's no evidence whether the bit keeps effect
persistently. But, judging from the experiment, it looks enough to
set it up once at the device initialization.
The patch is basically a cut from the original patch by Pierre-Louis
Bossart.
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_reg.h | 3 +++
drivers/gpu/drm/i915/intel_lpe_audio.c | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4e24ba0cdbe8..4f15a3dc6d98 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2062,6 +2062,9 @@ enum skl_disp_power_wells {
#define I915_HDMI_LPE_AUDIO_SIZE 0x1000
/* DisplayPort Audio w/ LPE */
+#define VLV_AUD_CHICKEN_BIT_REG _MMIO(VLV_DISPLAY_BASE + 0x62F38)
+#define VLV_CHICKEN_BIT_DBG_ENABLE (1 << 0)
+
#define _VLV_AUD_PORT_EN_B_DBG (VLV_DISPLAY_BASE + 0x62F20)
#define _VLV_AUD_PORT_EN_C_DBG (VLV_DISPLAY_BASE + 0x62F30)
#define _VLV_AUD_PORT_EN_D_DBG (VLV_DISPLAY_BASE + 0x62F34)
diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
index d3ffe0012692..3ba2799e93bd 100644
--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
+++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
@@ -248,6 +248,13 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
goto err_free_irq;
}
+ /* enable chicken bit; at least this is required for Dell Wyse 3040
+ * with DP outputs (but only sometimes by some reason!)
+ */
+ I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
+ I915_READ(VLV_AUD_CHICKEN_BIT_REG) |
+ VLV_CHICKEN_BIT_DBG_ENABLE);
+
return 0;
err_free_irq:
irq_free_desc(dev_priv->lpe_audio.irq);
--
2.11.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio
2017-02-02 17:02 ` [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Takashi Iwai
@ 2017-02-02 17:07 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-02-02 17:07 UTC (permalink / raw)
To: alsa-devel; +Cc: Pierre-Louis Bossart, Jerome Anand
On Thu, 02 Feb 2017 18:02:15 +0100,
Takashi Iwai wrote:
>
> The audio chicken bit (register offset 0x62f38) seems required to make
> DP audio working on some machines. At least, on Dell Wyse 3040, I
> failed to get the audio unless this bit is set once.
>
> Strangely, the bit seems necessary only once, and it persists after
> that, even some power-off cycles. The register is supposedly
> write-only, so it's no evidence whether the bit keeps effect
> persistently. But, judging from the experiment, it looks enough to
> set it up once at the device initialization.
>
> The patch is basically a cut from the original patch by Pierre-Louis
> Bossart.
>
> Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Sorry, this one is just a resend by mistake (I forgot to clean up
while sending the other patch series). Please disregard.
Takashi
^ permalink raw reply [flat|nested] 6+ messages in thread
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Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2017-02-02 10:12 [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Takashi Iwai
2017-02-03 13:32 ` Takashi Iwai
2017-02-03 14:54 ` Ville Syrjälä
2017-02-03 15:18 ` Takashi Iwai
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2017-02-02 17:02 [PATCH 00/53] Intel LPE audio driver cleanups Takashi Iwai
2017-02-02 17:02 ` [PATCH] drm/i915: Enable VLV audio chicken bit for LPE audio Takashi Iwai
2017-02-02 17:07 ` Takashi Iwai
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