[alsa-devel] Constant noise on HDA ALC275

[Takashi Iwai]

At Mon, 08 Oct 2012 18:52:26 +0200,
Julien Danjou wrote:
> 
> On Mon, Oct 08 2012, Takashi Iwai wrote:
> 
> > Yep, as David pointed out, the beep control overrides the amp setup.
> > And your previous result suggested that we shouldn't use this beep
> > path either (except for unmuting it), otherwise you get a noise
> > again.
> >
> > So, the patch below is the revised version.  It removes the beep
> > control but still opens the path to NID 0x1d.
> 
> It does remove the beep control, and I think it therefore break the beep
> functionnality: I've no sound when echoing '\a'. But that's likely to be
> expected anyhow. :-/

Doesn't the beep work if you load pcspkr module?  It should be there
independently.

> But yeah, definitely, I've no noise anymore in this case with this
> patch.
> 
> Now, I can still make the noise come back when "speaker" or "master" is
> muted. This is definitely not a side effect of your patch, I just didn't
> raise it before.

Hm, then maybe the effect of removing noise appears no matter which
input of NID 0x0b be unmuted?  

> This diff is between "no noise" (= just loaded the module with your
> patch) and "noise with master muted":
> 
> diff -u /tmp/no-noise.txt /tmp/noise-master-mute.txt
> --- /tmp/no-noise.txt	2012-10-08 18:36:44.601047347 +0200
> +++ /tmp/noise-master-mute.txt	2012-10-08 18:37:02.221050163 +0200
> @@ -3,7 +3,7 @@
>  !!ALSA Information Script v 0.4.61
>  !!################################
> 
> -!!Script ran on: Mon Oct  8 16:36:44 UTC 2012
> +!!Script ran on: Mon Oct  8 16:37:02 UTC 2012
> 
> 
>  !!Linux Distribution
> @@ -260,7 +260,7 @@
>      ControlAmp: chs=3, dir=Out, idx=0, ofs=0
>    Control: name="Speaker Phantom Jack", index=0, device=0
>    Amp-Out caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
> -  Amp-Out vals:  [0x00 0x00]
> +  Amp-Out vals:  [0x80 0x80]
>    Pincap 0x00010050: OUT EAPD Balanced
>    EAPD 0x2: EAPD
>    Pin Default 0x90170110: [Fixed] Speaker at Int N/A
> 
> 
> 
> 
> This diff is between "no noise" (= just loaded the module with your
> patch) and "noise with speaker muted":
> 
> diff -u /tmp/no-noise.txt /tmp/noise-speaker-mute.txt
> --- /tmp/no-noise.txt	2012-10-08 18:36:44.601047347 +0200
> +++ /tmp/noise-speaker-mute.txt	2012-10-08 18:37:10.913051519 +0200
> @@ -3,7 +3,7 @@
>  !!ALSA Information Script v 0.4.61
>  !!################################
> 
> -!!Script ran on: Mon Oct  8 16:36:44 UTC 2012
> +!!Script ran on: Mon Oct  8 16:37:10 UTC 2012
> 
> 
>  !!Linux Distribution
> @@ -260,7 +260,7 @@
>      ControlAmp: chs=3, dir=Out, idx=0, ofs=0
>    Control: name="Speaker Phantom Jack", index=0, device=0
>    Amp-Out caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
> -  Amp-Out vals:  [0x00 0x00]
> +  Amp-Out vals:  [0x80 0x80]
>    Pincap 0x00010050: OUT EAPD Balanced
>    EAPD 0x2: EAPD
>    Pin Default 0x90170110: [Fixed] Speaker at Int N/A

So, obviously muting the amp triggers the noise.
BTW, does the noise come only from speaker, not from headphone,
correct?

Related tests: what happens if you mute both input amps of the node
0x0d?  This is a mixer widget between DAC and the speaker pin.
Does this widget work as a proper mute/unmute point without causing
noise?


> Now, I've discovered one more thing, don't know if you know. This is how
> I managed to REALLY mute the speakers, the noise, everything (even
> playing a sound file with everything unmuted makes no sound):
> 
> % diff -u /tmp/sound.txt /tmp/no-sound-at-all.txt
> --- /tmp/sound.txt	2012-10-08 18:48:02.605161041 +0200
> +++ /tmp/no-sound-at-all.txt	2012-10-08 18:47:50.453158964 +0200
> @@ -3,7 +3,7 @@
>  !!ALSA Information Script v 0.4.61
>  !!################################
>  
> -!!Script ran on: Mon Oct  8 16:48:02 UTC 2012
> +!!Script ran on: Mon Oct  8 16:47:50 UTC 2012
>  
>  
>  !!Linux Distribution
> @@ -267,7 +267,7 @@
>      Conn = Analog, Color = Unknown
>      DefAssociation = 0x1, Sequence = 0x0
>      Misc = NO_PRESENCE
> -  Pin-ctls: 0x40: OUT
> +  Pin-ctls: 0x00:
>    Power states:  D0 D1 D2 D3 EPSS
>    Power: setting=D0, actual=D0
>    Connection: 2

This essentially disables the output of the speaker pin.

> When doing that, I cannot hear anything, because it seems to disconnect
> the speakers. My idea would be to set this pin to 0x00 instead of 0x40
> when "Speakers" are set to mute (I don't know about master though).
> WDYT?

Possible, but a bit hackish.  Let's see...


Takashi