[tlug] Reinstalling ALSA from source? Anybody tried?

[scott <scott@example.com>]

Hi everyone,

Nice to see snow in Tokyo yesterday, wasn't it :-)

 I've just installed Centos5.1 on a Toshiba M500 laptop, but I'm having
some problems with alsa. Some quick info about this system:

kernel: 2.6.18-53.1.4.el5xen
lspci audio hardware: 00:1b.0 Audio device: Intel Corporation 82801G
(ICH7 Family) High Definition Audio Controller (rev 02)

 The problem: alsamixer is missing the headphone and front faders so
there is no sound, and no way to unmute the nonexistent faders. Using
alsaunmute I can set Master and PCM volumes, but still no sound from
speakers or headphones. I've confirmed that the sound is working
however: if I crank up all the faders shown in alsamixer, there is a
faint "bleeding" of sound- the same effect you get in a normal mixer, so
it is playing the sound file properly, just not sending it to the right
channel, or the channel it is sending it to is muted/volume at 0%. 

 To further troubleshoot this problem I booted from a liveCD of
enterprise Sabayon and found the same bug- missing faders and no audio.
However on an identical M500 laptop with Kubuntu installed, alsamixer
has all the appropriate faders, headphone, front, etc, and the audio
works fine, from both the builtin speakers and headphones. The version
of alsamixer on Kubuntu is 1.0.11 whereas Centos5 is running v1.0.14rc4.

 I'm thinking if I roll back alsa to a previous version maybe it will
solve this problem. Of course, yum remove alsa will remove KDE and the
whole kitchen sink as well, so instead what I am thinking of doing is:

  rpm -e --nodeps alsa-lib-1.0.14-1.rc4.el5
  rpm -e --nodeps alsa-utils-1.0.14-2.rc4.el5

and then installing alsa from source. However from what I've read online
this is a pretty tough procedure, as alsa is referenced in the kernel,
etc.

Anyone tried something like this? Any last minute hints before I jump
into the abyss?

Cheers and thanks in advance for any suggestions,
Scott VanDusen
Tokyo