[Intel-gfx] [PATCH] drm: i915: Fix audio issue on BXT

[Runyan, Arthur J]

Abid or Hari, please check.  There was a workaround to set AUD_CHICKENBIT_REG bit 15 (Codec Wake overwrite to DACFEUNIT) on SKL and KBL.  Does it apply to BXT also?

> -----Original Message-----
> From: Pandiyan, Dhinakaran
> Sent: Monday, 26 February, 2018 6:04 PM
> To: Runyan, Arthur J <arthur.j.runyan at intel.com>; Singh, Gaurav K
> <gaurav.k.singh at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
> Nikula, Jani <jani.nikula at intel.com>
> Subject: RE: [Intel-gfx] [PATCH] drm: i915: Fix audio issue on BXT
> 
> 
> > -----Original Message-----
> > From: Runyan, Arthur J
> > Sent: Tuesday, January 9, 2018 11:55 AM
> > To: Pandiyan, Dhinakaran <dhinakaran.pandiyan at intel.com>; Singh,
> Gaurav K
> > <gaurav.k.singh at intel.com>
> > Cc: intel-gfx at lists.freedesktop.org; Vivi, Rodrigo <rodrigo.vivi at intel.com>
> > Subject: RE: [Intel-gfx] [PATCH] drm: i915: Fix audio issue on BXT
> >
> > Sorry, I've been out.  I'm checking on this.
> 
> 
> Hi Art,
> 
> Is AUD_CHICKENBIT_REG:15 needed for BXT to fix code enumeration issues?
> 
> -DK
> 
> >
> > -----Original Message-----
> > From: Pandiyan, Dhinakaran
> > Sent: Thursday, 4 January, 2018 2:00 PM
> > To: Singh, Gaurav K <gaurav.k.singh at intel.com>
> > Cc: intel-gfx at lists.freedesktop.org; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
> > subransu.s.prusty at intel.com; Runyan, Arthur J
> <arthur.j.runyan at intel.com>
> > Subject: Re: [Intel-gfx] [PATCH] drm: i915: Fix audio issue on BXT
> >
> > +Art
> >
> > On Thu, 2018-01-04 at 22:13 +0530, Singh, Gaurav K wrote:
> > >
> > > On 1/4/2018 2:48 AM, Rodrigo Vivi wrote:
> > > > On Wed, Jan 03, 2018 at 08:31:10PM +0000, Pandiyan, Dhinakaran
> wrote:
> > > >> On Thu, 2018-01-04 at 00:48 +0530, Gaurav K Singh wrote:
> > > >>> From: Gaurav Singh <gaurav.k.singh at intel.com>
> > > >>>
> > > >>> On Apollolake, with stress test warm reboot, audio card was not
> > > >>> getting enumerated after reboot. This was a
> > > >> The problem looks similar to
> > > >> https://lists.freedesktop.org/archives/intel-gfx/2017-October/14449
> > > >> 5.html
> > > >>
> > > >> although the proposed solutions are vastly different. I have Cc'd
> > > >> some more people.
> > > >>
> > > >>> spurious issue happening on Apollolake. HW codec and HD audio
> > > >>> controller link was going out of sync for which there was a fix in
> > > >>> i915 driver but was not getting invoked for BXT. Extending this
> > > >>> fix to BXT as well.
> > > >>>
> > > >>> Tested on apollolake chromebook by stress test warm reboot with
> > > >>> 2500 iterations.
> > > >>>
> > > >>> Signed-off-by: Gaurav K Singh <gaurav.k.singh at intel.com>
> > > >>> ---
> > > >>>   drivers/gpu/drm/i915/intel_audio.c | 2 +-
> > > >>>   1 file changed, 1 insertion(+), 1 deletion(-)
> > > >>>
> > > >>> diff --git a/drivers/gpu/drm/i915/intel_audio.c
> > > >>> b/drivers/gpu/drm/i915/intel_audio.c
> > > >>> index f1502a0188eb..c71c04e1c3f6 100644
> > > >>> --- a/drivers/gpu/drm/i915/intel_audio.c
> > > >>> +++ b/drivers/gpu/drm/i915/intel_audio.c
> > > >>> @@ -729,7 +729,7 @@ static void
> > i915_audio_component_codec_wake_override(struct device *kdev,
> > > >>>   	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
> > > >>>   	u32 tmp;
> > > >>>
> > > >>> -	if (!IS_GEN9_BC(dev_priv))
> > > >>> +	if (!IS_GEN9_BC(dev_priv) && !IS_BROXTON(dev_priv))
> > > >> IS_GEN9()? GLK might need this too.
> > > > I think this is applicable for all Gen9 platforms.
> > >
> > > > if GLK need there is the possibility of CNL also needing it...
> > > > So not sure where to stop.
> > > >
> > > > Also looking to the original patch that introduced this function,
> > > > commit '632f3ab95fe2 ("drm/i915/audio: add codec wakeup override
> > > > enabled/disable callback")'
> > > >
> > > > it tells that the reason was:
> > > > "In SKL, HDMI/DP codec and PCH HD Audio Controller are in different
> > > > p$ wells, so it's necessary to reset display audio codecs when power
> > > > we$ otherwise display audio codecs will disappear when resume from
> > > > low p$ state."
> > > >
> > > > Is this the case here on BXT?
> > > Yes, its the same case with BXT.
> > > >
> > > > Another interesting thing I noticed on Spec when searching for this
> > > > bit was that this bit is related to an workaround on SKL/KBL/CFL...
> > > > no mention to BXT.
> > > >
> > > > "This workaround is needed for an HW issue in SKL and KBL in which
> > > > HW codec and HD audio controller link was going out of sync."
> > > Yes, in Bspec it has been mentioned only for SKL and KBL. But without
> > > this fix, sound card was not getting enumerated for BXT.
> >
> >
> > Art,
> >
> > Can you please help us here? To summarize, the question is what platforms
> need
> > the AUD_CHICKENBIT_REG:15 bit to be set to avoid code enumeration
> failures?
> >
> > -DK
> >
> > > >
> > > > Thanks,
> > > > Rodrigo.
> > > >
> > > >>
> > > >>>   		return;
> > > >>>
> > > >>>   	i915_audio_component_get_power(kdev);
> > > >> _______________________________________________
> > > >> Intel-gfx mailing list
> > > >> Intel-gfx at lists.freedesktop.org
> > > >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > >