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Description of problem:
Somewhere between kernels 2.4.20-8 and kernel-2.4.20-13.9,
drivers/sound/ac97_codec.c was patched with changes that added the CMI brand of
codecs. These codecs don't have full-on PCM volume controls and the patch
disables access to these vestigal registers. The trouble is that writing 0 to
the PCM volume control mutes them. Disabling access to these registers prevents
the subsequent initialization routines from unmuting the digital audio outputs.
Hence, no sound.

To fix this, remove the flag AC97_NO_PCM_VOLUME from the CMI entries in
ac97_codec_ids[].



Version-Release number of selected component (if applicable):
kernel-2.4.20-18.9

How reproducible:
Always

Steps to Reproduce:
1. Get a sound system with a CMI ac97 codec (I've got an ECS K7S5A)
2. Install RH9 with the latest kernel & boot
3. Try to play digital audio

    

Actual Results:  No audible digital audio

Expected Results:  Should hear something

Additional info:

Here's the ac97_codec output from the syslog from my machine booting under
different kernels.

2.4.20-8
May 26 15:36:05 amadeus kernel: ac97_codec: AC97  codec, id: CMI65 (Unknown)

2.4.20-13.9
May 26 15:39:41 amadeus kernel: ac97_codec: AC97  codec, id: CMI65 (CMedia)
May 26 15:39:41 amadeus kernel: AC97 codec does not have proper volume support.