Re: Broken nforce3 support in ALSA on amd64?

[Takashi Iwai <tiwai@suse.de>]

At Sat, 26 Feb 2005 17:45:45 -0800,
Ian Forde wrote:
> 
> Note - in alsamixer, the only IEC958-related controls I see are "IEC958"
> and "IEC958 Playback AC97-SP5A", neither of which allow themselves to be
> muted...
> 
> It seems that because there's already a binary driver out there that can
> set the control bits correctly, all I should need to do is dump the
> registers after loading nvsound and playing both PCM and AC3 audio
> streams, then comparing them to what they look like when the
> corresponding ALSA module (snd-intel8x0) is loaded.  How would I go
> about doing that in a way that would be useful to get this driver
> working for me and included in the next ALSA release?

Nforce seems to route the SPDIF output not through ac97 codec but
directly to the SPDIF transmitter.  That's why ALSA driver doesn't
work.  It assumes the AC97 codec output.  So, apparently, we need to
find out unknown registers to set up IEC958 status bits.

Unfortunately, the datasheet of nforce is not available at all, so we
have no chance to fix this problem yet unless you do some reverse
engineering (but I never recommend to do that, it's a waste of time).


Takashi


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click