Re: [Alsa-user] Unable to get SPDIF Optical Audio working

[Ian F. <ia...@du...>]

On Tue, 2005-02-22 at 22:56 -0500, Robert Schultz wrote:
> Eric Jorgensen wrote:
> 
> >
> >   Not an nforce expert, but have you tried muting the iec958 channel?
> >that's the trick on via boards. 
> >  
> >
> 
> I just tried muting it, no luck.
> I have 'IEC958' and 'IEC958 Playback AC97-SPSA' in the alsamixer
> Only the first one is able to be muted, and doing so has no effect.

I'm running into the same problem, sort of.  In fact, mine's a little
stranger.  Motherboard is a DFI Lanparty UT 250GB nforce3.  I can get
PCM audio to route through the spdif correctly with ALSA.  But with AC3
audio, the blue light on my Sony receiver lights up but plays no sound.

lspci -v output from the chip:

00:06.0 Multimedia audio controller: nVidia Corporation nForce3 250Gb
AC'97 Audio Controller (rev a1)
        Subsystem: nVidia Corporation: Unknown device 0c11
        Flags: bus master, 66Mhz, fast devsel, latency 0, IRQ 177
        I/O ports at d300 [size=256]
        I/O ports at d400 [size=128]
        Memory at e9000000 (32-bit, non-prefetchable) [size=4K]
        Capabilities: [44] Power Management version 2

Here's the weird bit:  Following these steps in order allows me to play
AC3 through the SPDIF but no longer PCM audio:

1. Load ALSA modules
2. Play (successfully) PCM audio via:
	/usr/bin/mplayer -vo null -ao alsa:device=hw=0.2 somemoviefile.avi
3. Unload ALSA modules
4. Load nvsound module
5. Play (successfully) AC3-enabled audio via:
	/usr/bin/mplayer -vo null -ao oss -ac hwac3, someothermovie.vob
6. Unload nvsound module
7. Load ALSA modules
8. Play (successfully) AC3-enabled audio via:
	/usr/bin/mplayer -vo null -ao alsa:device=hw=0.2 -ac hwac3,
someothermovie.vob

And no - at this point, redoing step 2 at this point does *NOT* work.
Unless I unload alsa, load oss, play something PCM, unload oss, and load
alsa again... just tested that.

Kernel is FC3 2.6.10-1.760_FC3 with ALSA 1.0.8 from atrpms on a x86_64
platform.

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...

Maddening, isn't it? ;)

	-I