Dual simulatenous output on single card not recognized

Eldred HABERT stuff at eldred.fr
Sun Nov 28 14:28:05 CET 2021


Hello,

I bought a laptop with integrated sound output (either to speakers or 
headphones), and a HDMI output. Attached is the output of `aplay -l`.

Under both PipeWire and PulseAudio, I only get a single output/sink (by 
default to the built-in output), but I can get simultaneous output to both:
- under PulseAudio, by adding a `load-module module-alsa-sink 
device=hw:0,7` line to the config;
- under PipeWire, by adding a profile to the card to enable both 
outputs, which correctly provides two outputs that work fine concurrently.

I was directed to this mailing list after the following discussion:

 > It's a kernel ALSA bug if SOF actually must contain enough data for 
the driver to figure this out (or at least pass that data on to 
userspace to deal with it)
 > if [we are] right that hardware itself does not contain the required 
data, then it can only be fixed in userspace via a card database
 > which is one thing to do, another would be maybe a heuristic rule 
that attempts to guess if such cards with analog and digital sub-devices 
might be independent

Please tell me if more details are needed—it would be nice if hardware 
configurations like mine could be fully supported out of the box ^^

Cheers,
~ ISSOtm
-------------- next part --------------
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC892 Digital [ALC892 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0


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