[bug report] 'ASoC: Intel: haswell: Power transition refactor' and PulseAudio

[Cezary Rojewski]

On 2020-08-31 11:55 PM, Christian Bundy wrote:
> After upgrading to Linux 5.8 I discovered an audio issue on my device that was introduced in 8ec7d6043263ecf250b9b7c0dd8ade899487538a [0]. I used 'git bisect' to identify the commit that introduced the bug and have confirmed that reverting the commit resolves the problem
> 
> Reproduction:
> 
> 1. Play any audio via PulseAudio.
> 2. Observe that the audio output is fuzzy and choppy.
> 
> I can use programs like mpv to play audio without PulseAudio, and the audio is fine, but as soon as I open a process that uses PulseAudio it will ruin the audio output for all processes (including mpv) until I reboot.
> 
> I'm using a 2015 Chromebook Pixel ("Samus") and have confirmed this problem with a friend who has the same device.
> 
> Is there anything I can do to help debug this instead of sending a patch to revert the commit?
> 

Hello Christian,

Thank you for report! Issue is a known one to us and has already been 
addressed by:

	[PATCH v4 00/13] ASoC: Intel: Catpt - Lynx and Wildcat point
	https://www.spinics.net/lists/alsa-devel/msg113762.html

waiting for final dependency to be merged (Andy's resource-API changes, 
as Mark already added the SPI ones) so v5 with review changes can be 
provided. Shouldn't be long before this gets merged. As consequence, 
/haswell/ ceases to exist.

Basically, once power-cycle (D0 -> D3 -> D0 transition flow) had been 
fixed, more - previously hidden - problems arisen. Instead of sending 
70+ patches to Mark refactoring existing code to recommended flow (+ 
readability and performance improvements), replacement is provided along 
with old code being removed entirely.

For now, if there's a possibility for you to modify your kernel, said 
patch can be safely removed from your local repo. Note: following is the 
outcome:
- DMA init may occasionally fail on early boot (audio card won't be 
present at all, requires reboot)
- D0/D3 flow doesn't follow recommended sequence and thus power-saving 
may be limited or non-existent
Probably still better than permanently fuzzied audio..

I'm sorry for any inconvenience this has caused to you.

Regards,
Czarek