[alsa-devel] hda: broken PCM over spdif after AC3; suggestion

Takashi Iwai tiwai at suse.de
Tue Oct 21 08:32:17 CEST 2008

At Tue, 21 Oct 2008 02:37:28 +0200,
Tomas Cernaj wrote:
> Hello,
> trying to track down a long standing bug concerning PCM output over
> spdif and analog ports simultaneously after AC3 passthrough (see
> https://bugs.launchpad.net/bugs/25632 ), I've been digging into the
> inner workings of HD Audio...
> It seems to me that after playing DVDs with AC3 passthrough the stream
> associated with the default alsa device is only connected to the front
> Audio Output widget but not at the same time to the Digital output
> widget, as I would have expected. I've attached the contents
> of /proc/asound/Intel/codec#0 during music playback to this mail; you
> can see the different streams connected to nodes 0x02 and 0x03.
> I'm not familiar with the hda driver, but I suspect that after AC3
> passthrough the multi-out configuration isn't reset to what it's
> supposed to be.
> Is there a way to work around this issue, or am I completely missing the
> point?

I didn't check the launchpad page yet, but did you set "IEC958 Default PCM"
switch off?  Or, start AC3 stream first, then analog stream.

The "IEC958 Default PCM" switch determines whether the SPDIF stream is
assigned to the "default" PCM or not.


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