[Pkg-alsa-devel] Bug#366212: Sound server CPU overload: workaround

[Nick Leverton]

Spurred by Elimar's cryptic hint, I did some research on this and found
a simple workaround.  The upstream bug reference is here:
https://bugtrack.alsa-project.org/alsa-bug/view.php?id=2067

There's a hardware feature called DXS which lets the chip play several
streams at once.  In many VIA chips this is poor quality or even buggy,
so the ALSA drivers have a table of which chips don't work or need
workarounds.  I guess maybe our VT8233/A/8235/8237 AC97 Audio Controller
(rev 50) or (rev 60) aren't correctly represented in this table.
http://alsa.opensrc.org/index.php?page=via8233

Slackware say that driver versions 1.0.11-rc4 and earlier don't have
the problem: http://lwn.net/Articles/181557/ so if you can downgrade to
1.0.10 from snapshot.debian.net it may work for you.

Alternatively try disabling the DXS system completely - I have Debian
ALSA 1.0.11, I disabled DXS on my rev 50, and I now have sound !
This is how.  Possibly some of it is redundant, as I've not kept up with
the ever-changing module scene, but it works:

Create a file /etc/modutils/00local containing one line:

  options snd-via82xx dxs_support=2

Run update-modules (in case you have a setup that still uses modules.conf;
mine seems to prefer modprobe.d).

Link that file into /etc/modprobe.d:

  # ln -s /etc/modutils/00local /etc/modprobe.d/

Reboot, and enjoy :)

The other possible settings for dxs_support are documented at
http://alsa.opensrc.org/index.php?page=via8233 and it may be one of them
works for you if you absolutely need the DXS feature.

Nick
-- 
Googlebait: Sound server fatal error CPU overload, aborting