via82xx: unreliable audio, strange mixer behavior

[Forest Bond <forest@alittletooquiet.net>]

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.

This issue is impacting a significant project for me and my company.  I'm
willing to spend as much time as it takes to debug, and I'm fairly technical.  I
can also offer a bounty of some sort, if that interests anyone.

Can anyone offer any input?

Thanks,
Forest
--
Forest Bond
http://www.alittletooquiet.net
http://www.pytagsfs.org