[alsa-devel] Audio crackles with 4.1-rc1

[Mihai Donțu]

On Wed, 10 Jun 2015 12:50:22 +0200 Takashi Iwai wrote:
> At Wed, 10 Jun 2015 13:41:35 +0300, Mihai Donțu wrote:
> > On Wed, 10 Jun 2015 12:22:53 +0200 Takashi Iwai wrote:
> > > At Wed, 10 Jun 2015 13:17:55 +0300, Mihai Donțu wrote:
> > > > On Wed, 20 May 2015 07:01:12 +0200 Takashi Iwai wrote:
> > > > > From: Takashi Iwai <tiwai at suse.de>
> > > > > Subject: [PATCH] ALSA: hda - Disable widget power-saving for ALC292 & co
> > > > > 
> > > > > We've got reports that ALC3226 (a Dell variant of ALC292) gives click
> > > > > noises at transition from D3 to D0 when the widget power-saving is
> > > > > enabled.  Further debugging session showed that avoiding it isn't
> > > > > trivial, unfortunately, since paths are basically activated
> > > > > dynamically while the pins have been already enabled.
> > > > > 
> > > > > This patch disables the widget power-saving for such codecs.
> > > > > 
> > > > > Reported-by: Jonathan McDowell <noodles at earth.li>
> > > > > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > > > > ---
> > > > >  sound/pci/hda/patch_realtek.c | 3 ++-
> > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
> > > > > index 2e246fe495f6..31f8f13be907 100644
> > > > > --- a/sound/pci/hda/patch_realtek.c
> > > > > +++ b/sound/pci/hda/patch_realtek.c
> > > > > @@ -5623,7 +5623,8 @@ static int patch_alc269(struct hda_codec *codec)
> > > > >  
> > > > >  	spec = codec->spec;
> > > > >  	spec->gen.shared_mic_vref_pin = 0x18;
> > > > > -	codec->power_save_node = 1;
> > > > > +	if (codec->core.vendor_id != 0x10ec0292)
> > > > > +		codec->power_save_node = 1;
> > > > >  
> > > > >  	snd_hda_pick_fixup(codec, alc269_fixup_models,
> > > > >  		       alc269_fixup_tbl, alc269_fixups);
> > > > 
> > > > I'm on 4.1-rc7 which appears to contain this patch, however, I still
> > > > get the audio artifacts (crackles) when I boot my laptop (Latitude
> > > > E7440):
> > > > 
> > > > [    1.058839] snd_hda_codec_realtek hdaudioC1D0: autoconfig for ALC3226: line_outs=1 (0x16/0x0/0x0/0x0/0x0) type:line
> > > > [    1.058843] snd_hda_codec_realtek hdaudioC1D0:    speaker_outs=1 (0x14/0x0/0x0/0x0/0x0)
> > > > [    1.058846] snd_hda_codec_realtek hdaudioC1D0:    hp_outs=1 (0x15/0x0/0x0/0x0/0x0)
> > > > [    1.058849] snd_hda_codec_realtek hdaudioC1D0:    mono: mono_out=0x0
> > > > [    1.058851] snd_hda_codec_realtek hdaudioC1D0:    inputs:
> > > > [    1.058855] snd_hda_codec_realtek hdaudioC1D0:      Dock Mic=0x19
> > > > [    1.058859] snd_hda_codec_realtek hdaudioC1D0:      Headset Mic=0x1a
> > > > [    1.058862] snd_hda_codec_realtek hdaudioC1D0:      Internal Mic=0x12
> > > > 
> > > > 4.0.4 was fine.
> > > 
> > > Does it happen only once at boot (i.e. at power up), or happens always
> > > at runtime PM?  If it's a once-off boot thing, the patch shouldn't
> > > have much effect.  Something else, very subtle thing, e.g. the order
> > > of verb execution, might cause this kind of problem.
> > 
> > Only at power up. I've also suspend-resumed twice and can confirm it's
> > OK.
> > 
> > There's a _very_ brief click at suspend (when the power is cut), but it
> > looks like a plain circuitry thing. I probably didn't notice it before
> > because I wasn't looking for it.
> 
> Thanks.  Do you get the same click noise when reloading snd-hda-intel
> driver?  Also, does it happen when booting in runlevel 3?
> 
> Last but not least, a patch like below has any effect?
> 
> 
> Takashi
> 
> ---
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -3077,6 +3077,8 @@ static unsigned int hda_set_power_state(struct hda_codec *codec,
>  			break;
>  	}
>  
> +	if (power_state == AC_PWRST_D0)
> +		msleep(100);
>  	return state;
>  }
>  

Reloading snd-hda-intel does not trigger the noise, but it helps. I've
noticed that the clicks appear when loading/reloading pulseaudio.

  $ pulseaudio -k

will spawn a new child in background (probably asked by kmix) and
immediately I hear the noise. Reloading the driver makes the problem go
away.

telinit 3 does nothing for me (Gentoo seems to have things wired
differently). Manually reloading alsasound (/etc/init.d/alsasound) did
not trigger the problem either.

However! Your patch seems to work. Cold boot, pulseaudio restart and
nothing. Not a peep. :-)

-- 
Mihai Donțu