[alsa-devel] via82xx: unreliable audio, strange mixer behavior

[Takashi Iwai]

At Thu, 20 Nov 2008 12:04:09 -0500,
Forest Bond wrote:
> 
> Hi,
> 
> I'm using snd-via82xx on an Ubuntu 8.04 system.  alsa-info.sh output is here:
> 
> http://www.alsa-project.org/db/?f=1c3d5570e7b57d4d2f79b964a323dd7b4efd7e78
> 
> Here are the symptoms:
> 
> Audio goes away after a semi-random interval.  Sometimes it returns after
> `modprobe -r snd-via82xx' followed by `modprobe snd-via82xx', but sometimes it
> seems to take a full reboot.
> 
> This looks similar to:
> 
> https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3D3194
> 
> Some folks think that this kind of issue is triggered by audio volume being
> above a certain level.  I'm not entirely sure if this is true, but I think it
> is.  One time, I apparently triggered the issue by unplugging and replugging the
> audio cable from the mainboard during playback.
> 
> Audio can be heard even when the PCM volume level is 0 (as told by alsamixer).
> The volume does get louder when I turn up that mixer control, but it never goes
> away entirely when I turn the volume to zero.  Mute works as expected.

The volume 0 doesn't always mean the mute on several hardwares.
So this can be irrelevant if it happens always.

I vaguely remember about the low-power mode of some codec chips.
Which codec chip does your system have?  Please run alsa-info.sh with
--no-upload option, and attach the output file.


Takashi