Re: Regression apparently caused by commit 088a40980efbc2c449b72f0f2c7ebd82f71d08e2 "ASoC: amd: acp: add pm ops support for acp pci driver"

[Bagas Sanjaya]

On 03/11/2023 20:30, syed saba kareem wrote:
> 
> On 11/3/23 04:41, Bagas Sanjaya wrote:
>> On Thu, Aug 03, 2023 at 10:22:07PM +0300, Marian Postevca wrote:
>>> I'm trying to develop a sound machine driver based on the acp legacy driver.
>>> The first version of the driver was sent for review on the alsa mailing list this
>>> spring: https://lore.kernel.org/all/20230320203519.20137-1-posteuca@xxxxxxxxx
>>>
>>> I'm trying to fix some of the issues that were brought up during the review back then,
>>> but when I ported the patches to the latest commit on the for-next
>>> branch, I noticed a regression where I couldn't hear any sound at all.
>>>
>>> So I started a bisect session and found that the first bad commit is:
>>> ASoC: amd: acp: add pm ops support for acp pci driver
>>> commit 088a40980efbc2c449b72f0f2c7ebd82f71d08e2
>>> https://lore.kernel.org/lkml/20230622152406.3709231-11-Syed.SabaKareem@xxxxxxx
>>>
>>> If I revert this commit sound works as expected. So I started tinkering a little bit
>>> with it and I believe that what happens is that the acp pci driver
>>> enters the autosuspend state and never leaves this state at all.
>>> I noticed this because if I increase the autosuspend delay to a much
>>> larger value, then the sound works until that delay passes.
>>> I added traces and I can see that when the delay expires the suspend callback snd_acp_suspend()
>>> gets called, but the resume callback snd_acp_resume() never gets called.
>>>
>>> I'm no expert in runtime power management (though I did read a bit on it), so I don't understand
>>> all the things that happen underneath, but one thing that is not clear to me is who's supposed
>>> to mark activity on this device and keep it from entering autosuspend if the user wants to play
>>> some sound? Shouldn't there be some counterpart that calls pm_runtime_mark_last_busy() ?
>>> I looked through the code and can't find who's calling pm_runtime_mark_last_busy().
>>>
>>> Some help here would be welcome. Is there something missing in my machine driver code, or
>>> is the runtime pm handling in acp pci driver wrong?
>> Thanks for the regression report. I'm adding it to regzbot:
>>
>> #regzbot ^introduced: 088a40980efbc2
>>
> We were working on some other priority tasks, will upstream the changes
> 
> by next week.
> 

OK, thanks!

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