Re: [PATCH] ALSA: hda/realtek: Fix pop noise on ALC225

[Kai-Heng Feng]

> On Mar 11, 2020, at 14:54, Takashi Iwai <tiwai@xxxxxxx> wrote:
> 
> On Wed, 11 Mar 2020 07:13:28 +0100,
> Kai-Heng Feng wrote:
>> 
>> Commit 317d9313925c ("ALSA: hda/realtek - Set default power save node to
>> 0") makes the ALC225 have pop noise on S3 resume and cold boot.
>> 
>> So partially revert this commit for ALC225 to fix the regression.
>> 
>> Fixes: 317d9313925c ("ALSA: hda/realtek - Set default power save node to 0")
>> BugLink: https://bugs.launchpad.net/bugs/1866357
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
>> ---
> 
> Hrm, it's rather surprising.  The power_save_node was thought to be a
> cause of the pop noise, but in this case it fixes.  It's interesting
> because this codec chip has no loopback mixer, and the connection is
> directly from DAC to pin, so in theory, it shouldn't be influenced
> from other nodes.
> 
> Anyways, a slight concern is that this might cause a regression on
> another machine.  But who knows, maybe the influence is very limited.
> Let's apply it and see what happens.

If that happens I'll write a specific fixup for the affected model.

Kai-Heng

> 
> 
> thanks,
> 
> Takashi