[alsa-devel] [RFC PATCH 4/5] drm: i915: add DisplayPort amp unmute for LPE audio mode

[Takashi Iwai]

On Fri, 27 Jan 2017 15:35:47 +0100,
Ville Syrjälä wrote:
> 
> On Fri, Jan 27, 2017 at 03:17:34PM +0200, Ville Syrjälä wrote:
> > On Fri, Jan 27, 2017 at 12:08:58PM +0200, Jani Nikula wrote:
> > > On Thu, 26 Jan 2017, Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com> wrote:
> > > > Enable chicken bit on LPE mode setup and unmute amp on
> > > > notification
> > > >
> > > > FIXME: should these two phases done somewhere else?
> > > >
> > > > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/i915_reg.h        | 12 ++++++++++++
> > > >  drivers/gpu/drm/i915/intel_lpe_audio.c | 27 +++++++++++++++++++++++++++
> > > >  2 files changed, 39 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > > index a9ffc8d..ee90f64 100644
> > > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > > @@ -2061,6 +2061,18 @@ enum skl_disp_power_wells {
> > > >  #define I915_HDMI_LPE_AUDIO_BASE	(VLV_DISPLAY_BASE + 0x65000)
> > > >  #define I915_HDMI_LPE_AUDIO_SIZE	0x1000
> > > >  
> > > > +/* DisplayPort Audio w/ LPE */
> > > > +#define CHICKEN_BIT_DBG_ENABLE		(1 << 0)
> > > > +#define AMP_UNMUTE		        (1 << 1)
> > 
> > That should be called AMP_MUTE I think,
> > 
> > > 
> > > The convention is to define registers first and the contents/bits for
> > > each register immedialy below. For groups of registers (like
> > > PORT_EN_B/C/D below) define all registers first and bits immediately
> > > below. (But note that the chicken register is not part of the group.)
> > > 
> > > > +#define AUD_CHICKEN_BIT_REG		0x62F38
> > 
> > Spec calls this AUD_CHICKENBIT_REG. Might as well follow it to the
> > letter.
> > 
> > > > +#define AUD_PORT_EN_B_DBG		0x62F20
> > > > +#define AUD_PORT_EN_C_DBG		0x62F28
> > > > +#define AUD_PORT_EN_D_DBG		0x62F2C
> > 
> > These match the spec. But to match the standard i915 convention they
> > should be called _AUD_PORT_EN_B_DBG etc. Same forthe chicken bit
> > register.
> 
> Actually they just match one version of the spec I had lying around.
> Another versions says:
> 
> AUD_PORT_EN_B_DBG 0x62F20
> AUD_PORT_EN_C_DBG 0x62F30
> AUD_PORT_EN_D_DBG 0x62F34

That's it!  Now finally I can hear the audio from DP3 with the
additional patch below.


thanks,

Takashi

---
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ee90f64b89e8..5c577d242078 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2066,8 +2066,8 @@ enum skl_disp_power_wells {
 #define AMP_UNMUTE		        (1 << 1)
 #define AUD_CHICKEN_BIT_REG		0x62F38
 #define AUD_PORT_EN_B_DBG		0x62F20
-#define AUD_PORT_EN_C_DBG		0x62F28
-#define AUD_PORT_EN_D_DBG		0x62F2C
+#define AUD_PORT_EN_C_DBG		0x62F30
+#define AUD_PORT_EN_D_DBG		0x62F34
 #define VLV_AUD_CHICKEN_BIT_REG		_MMIO(VLV_DISPLAY_BASE + AUD_CHICKEN_BIT_REG)
 #define VLV_AUD_PORT_EN_B_DBG		_MMIO(VLV_DISPLAY_BASE + AUD_PORT_EN_B_DBG)
 #define VLV_AUD_PORT_EN_C_DBG		_MMIO(VLV_DISPLAY_BASE + AUD_PORT_EN_C_DBG)