More on Blade 100/AC97 codec detection failure

[J.C. Wren]

I've done a little bit more playing around, trying to get sound working on the 
Blade 100.  First, ac97_codec.c is reading an ID of 0x00000000 for the codec.  
It's supposed to be 0x41445348 (AD1881A).  I didn't have much hope that 
forcing the codec ID to that value would solve anything, and sure enough, it 
didn't.  There are two ambiguous comments in the codec detection area:

       /* probing AC97 codec, AC97 2.0 says that bit 15 of register 0x00 
(reset) should
         * be read zero.
         *
         * FIXME: is the following comment outdated?  -jgarzik
         * Probing of AC97 in this way is not reliable, it is not even SAFE !!
         */

So which is it?

I have talked to another person with a Blade 100, using 2.4.21-rc6 (I'm on 
-rc4), and they have the EXACT same problem.  So I'm not hallucinating, 
unless we all shared the Koolaid.

I don't know the significance of this but using mpg123 to play a MP3 gives no 
audio.  Using mpg321 produces a loud hissing *way* over-amped audio that one 
can vaguely here modulation on.  It sounds like the rate is off somewhat, but 
the only way I can even remotely tell that is to use a gain of 1 (-g 1) to 
mpg321.  To even get mpg123 to work, I had to modprobe in the 'dmy' device 
and give it a fake /dev/audioctl to play with itself with.

The other person with the Blade 100 reported that 2.4.20-r8 produced the same 
hissy results.  However, there are reports of people using Debian with 2.4.18 
having it work (http://www.de-brauwer.be/docs/debian_on_sun.html).

--jcwren