Re: [PATCH v2 00/11] Fix support for System Suspend for CS35L41 HDA

[Takashi Iwai <tiwai@suse.de>]

On Mon, 24 Jul 2023 11:00:38 +0200,
Takashi Iwai wrote:
> 
> On Fri, 21 Jul 2023 17:18:05 +0200,
> Stefan Binding wrote:
> > 
> > There have been a couple of customer reports of intermittant issues after
> > system resume, where sometimes the DSP firmware stops responding.
> > Investigations into this issue show that there is a race between receiving
> > a prepare from the HDA core, and the firmware reload which is started by
> > the system resume. This can causes the Global Enable on the CS35L41 to be
> > enabled during the firmware load, which can sometimes cause issues in the
> > DSP.
> > 
> > The existing system resume behaviour also did not resume the audio, if
> > audio was previously playing when it was suspended.
> > In addition, during investigation, it was found there were additional
> > problems in the System Resume sequence, as well as the Playback sequence
> > with External Boost, where the driver does not correctly follow its
> > enable sequence for this mode. This can cause additional issues such as
> > pops and clicks.
> > 
> > This chain intends to correct the sequences for playback and system
> > suspend/resume so that the driver: obeys the external boost enable sequence;
> > resumes audio on system resume; and avoids the race condition on firmware
> > load and playback during system resume.
> > 
> > Changes since v1:
> > - Split patch 1 into 2 separate patches
> > - Combine Patches 6 and 9
> > 
> > Stefan Binding (11):
> >   ALSA: cs35l41: Use mbox command to enable speaker output for external
> >     boost
> >   ALSA: cs35l41: Poll for Power Up/Down rather than waiting a fixed
> >     delay
> >   ALSA: hda: cs35l41: Check mailbox status of pause command after
> >     firmware load
> >   ALSA: hda: cs35l41: Ensure we correctly re-sync regmap before system
> >     suspending.
> >   ALSA: hda: cs35l41: Ensure we pass up any errors during system
> >     suspend.
> >   ALSA: hda: cs35l41: Move Play and Pause into separate functions
> >   ALSA: hda: hda_component: Add pre and post playback hooks to
> >     hda_component
> >   ALSA: hda: cs35l41: Use pre and post playback hooks
> >   ALSA: hda: cs35l41: Rework System Suspend to ensure correct call
> >     separation
> >   ALSA: hda: cs35l41: Add device_link between HDA and cs35l41_hda
> >   ALSA: hda: cs35l41: Ensure amp is only unmuted during playback
> 
> Applied all patches now to for-next branch.

It seems that this patch set causes occasional freeze at suspend:
  https://bugzilla.suse.com/show_bug.cgi?id=1213745

Could you take a look?


thanks,

Takashi