snd_hda same output on two pcms?

[J.R. Oldroyd]

Is it possible to configure snd_hda so that one output is available
on two pcm devices?

I would like:
pcm0: built-in speaker, headphone jack
mic

pcm1: built-in speaker only

My default hda config is here:

http://opal.com/jr/snd_hda/default.txt

I added the following device hints:

hint.hdac.0.cad3.nid20.config="as=1 seq=0"
hint.hdac.0.cad3.nid21.config="as=1 seq=15"
hint.hdac.0.cad3.nid24.config="as=2 seq=0"
hint.hdac.0.cad3.nid25.config="as=2 seq=1"
hint.hdac.0.cad3.nid22.config="as=3 seq=0 device=Speaker conn=Fixed"

The result is here:

http://opal.com/jr/snd_hda/changed.txt

The result is that pcm0 works as expected, but the initialization
of pcm1 fails, as can be seen in the trace:

hdac0: Tracing association 2 (3)
hdac0: Unable to trace pin 22 seq 0 with min nid 0
hdac0: Association 2 (3) trace failed

I also tried:

hint.hdac.0.cad3.nid22.config="0x99130130"

with the same failed result.

I note the last paragraph in the snd_hda man page:

BUGS
Due to OSS limitation multichannel (not multidevice) playback
is not supported.

Does that mean I cannot do what I am attempting to do?

-jr

[Alexander Motin]

Post by J.R. Oldroyd
Is it possible to configure snd_hda so that one output is available
on two pcm devices?
pcm0: built-in speaker, headphone jack
mic
pcm1: built-in speaker only

If I understand right, you want to configure hardware mixing. Most of
HDA codecs unable to do it in hardware. Some other are able, but this is
not supported by the driver. It tries to isolate pcmX devices one from
another.