Re: [PATCH] ALSA: hda: fix snd_hda_bus_reset when single_cmd is not supported

[Takashi Iwai <tiwai@suse.de>]

On Mon, 26 Aug 2024 11:19:58 +0200,
soxiebing wrote:
> 
> >On Wed, 21 Aug 2024 03:42:38 +0200,
> >soxiebing wrote:
> >> 
> >> From: songxiebing <songxiebing@kylinos.cn>
> >> 
> >> When an azx_get_desponse timeout occurs, ensure that bus_reset
> >> can be used when fallback_to_single_cmd is not supported.
> >> 
> >> Signed-off-by: songxiebing <songxiebing@kylinos.cn>
> >
> >Why do you need to change?  Does it fix any real problem you faced?
> 
> Thanks for reply, i am testing all these days, but the problem is
> still exists even if using bus reset.
>
> The problem i encountered is that hda_call_codec_resume returned 
> timeout of 120 seconds(defined CONFIG_DPM_WATCHDOG)) when doing s4, 
> azx_get_response timeout occured, it is a low probability event.
> 
> To avoid exceeding 120s, can i change the count value to 3 in 
> hda_set_power_state ?

So the change you suggested isn't for any real "fix" but to allow the
possible workaround with single_cmd to be applicable somehow in a
different form.  Then we should rather try debugging the original
issue, instead of change it.

Does the response timeout happen *during* the S4 suspend, or during S4
resume, or after S4 resume?

To be noted, the behavior you changed is only for the single_cmd
option is set explicitly, so it's more or less the designed behavior,
and I don't think it's good to change blindly.


Takashi