[alsa-devel] CPU hook snd_hda_intel

[Takashi Iwai]

On Mon, 02 Dec 2019 19:47:59 +0100,
Klaus Ethgen wrote:
> 
> Hello,
> 
> Please keep me in Cc when you answer as I am not subscribed to the list.
> 
> I use the most current kernel 5.4.1 (but I did have that problem since
> several 5.x versions) on gentoo on a X61s Lenovo laptop. What I see is
> that from time to time one CPU is constantly working and draining my
> battery with a process kworker/*-events.
> 
> Today I was able to identify the source of the problem. The module
> snd-hda-intel seems to produce that load. When I unload the module, the
> CPU hook is gone. Even if I load it again, I have a good change to solve
> the problem.
> 
> It also helps often to put the laptop to sleep and waking it up again.
> 
> My relevant dmesg part is:
>    [    7.186766] snd_hda_intel 0000:00:1b.0: probe_mask set to 0x1 for device 17aa:20ac
>    [    7.563277] snd_hda_codec_generic hdaudioC0D0: autoconfig for Generic: line_outs=1 (0x12/0x0/0x0/0x0/0x0) type:speaker
>    [    7.563281] snd_hda_codec_generic hdaudioC0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
>    [    7.563284] snd_hda_codec_generic hdaudioC0D0:    hp_outs=1 (0x11/0x0/0x0/0x0/0x0)
>    [    7.563286] snd_hda_codec_generic hdaudioC0D0:    mono: mono_out=0x0
>    [    7.563288] snd_hda_codec_generic hdaudioC0D0:    inputs:
>    [    7.563292] snd_hda_codec_generic hdaudioC0D0:      Internal Mic=0x15
>    [    7.563294] snd_hda_codec_generic hdaudioC0D0:      Mic=0x14
>    [    7.563297] snd_hda_codec_generic hdaudioC0D0:      Dock Mic=0x1c
> 
> For reference I attach my kernel config to this mail. I am not sure if
> it is needed but better give as much as informations that I have.
> 
> So please, if you have any idea how to narrow that problem or even solve
> it, help would be appreciated.

I guess checking the perf output would give you more clue, e.g. which
function is hogging the CPU.  Without such information, it's very hard
to diagnose...


thanks,

Takashi