mixer problems with SiS 7012 and CMI9761 ac97 codec

	Hello all,



I'm seeing quite weird symptoms with this onboard SiS 7012 audio
controller.  The "pcm" mixer setting doesn't change the sound's volume
at all, except at 0 where it mutes the sound as expected.  The "vol"
mixer setting has absolutely no control over sound, it doesn't change
anything whether I set it to 0 or 100.

If I set the "speaker" mixer setting to 0, it outputs a very loud beep.
If I set it to 1, there is a small beep.  If I set it higher, up to 49,
the beep gets louder, and at 50 and above it doesn't output the beep
anymore.  I don't have a "ogain" channel.  Interesting, isn't it? :-)

As said in the topic, this is a SiS 7012 sound card.  It has a CMI9761
ac97 codec (id == 0x434d4982 == "CMI" 0x82).  It isn't in the list of
supported codec ids on FreeBSD.  It is however listed in ALSA's source
code, and has chipset specific support code.  I merged one of the
workaround, which is for the specific revision of the CMI9761 chipset I
have.  Unfortunately, nothing changed.

I wonder if anyone else is having problems with this chipset/ac97 codec,
or if it's working fine for others.  If someone more knowledgeable than
me in AC97 code is interested to look at the problem, I'd be glad.  I
don't know enough about this to even know where exactly the problem may
lie.

Cheers,
Maxime