Re: Regression in v5.19-rc4 Sound Distortion

From: Thorsten Leemhuis
Date: Thu Jul 14 2022 - 01:22:41 EST




On 13.07.22 12:12, Daniel Exner wrote:
> horsten Leemhuis wrote:
>> On 12.07.22 18:35, Dmitry Osipenko wrote:
>>> On 7/12/22 19:02, Daniel Exner wrote:
>>>
>>>> Since  v5.19-rc4 this box got some *loud* distorting sound on boot and
>>>> after some time without any sound if something plays sound again from
>>>> the integrated speakers in my monitor.
>>>>
>>>> I managed to bisect this down to:
>>>>
>>>>> commit 202773260023b56e868d09d13d3a417028f1ff5b
>>>>> Author: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
>>>>> Date:   Fri Jun 17 15:24:02 2022 +0300
>>>>>
>>>>>     PM: hibernate: Use kernel_can_power_off()
>>>> Reverting that commit on top of v5.19-rc6 does indeed fix the
>>>> problem here.
>>> You're saying that the problem is on boot, but this patch is about
>>> suspension to disk, which has nothing to do neither with the boot nor
>>> with power-off. I'm afraid your bisection is incorrect.
>> After quickly looking at the code this looks appropriate, but why does
>> reverting that commit help then? That's a bit odd. Daniel: are you maybe
>> using suspend-to-disk and forgot to mention it?
>
> No, I am not. But it seems Dmitry was right, at some point I bisected
> wrong by declaring some point good too early because I didn't have the
> bug on boot.
>
> Perhaps I have two effects here: some bug resulting in sound distortion
> and some bug triggering that faster.

Happens, thx for letting us know.

> I will redo the bisection, but I fear it will take some time.

BTW, what was the last Linux version that actually worked? I'm tracking
this regressions with regzbot (https://gitlab.com/knurd42/regzbot/ ) and
it would be good to have that on record at least roughly. From the text
it was not totally clear. I assume it was something like this:

#regzbot introduced: v5.19-rc1..v5.19-rc4

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.