Dual simulatenous output on single card not recognized

Dual simulatenous output on single card not recognized

[Eldred HABERT]

[-- Attachment #1: Type: text/plain, Size: 1236 bytes --]

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

[-- Attachment #2: aplay-l --]
[-- Type: text/plain, Size: 789 bytes --]

**** 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

Re: Dual simulatenous output on single card not recognized

[Pierre-Louis Bossart]

On 11/28/21 7:28 AM, Eldred HABERT wrote:
> 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 ^^

You may want to run 'alsa-info' and provide a link to the uploaded
results. It's hard to comment without any information on 'hardware
configurations like mine'.
Thanks.

Re: Dual simulatenous output on single card not recognized

[Eldred HABERT]

On 29/11/2021 19:18, Pierre-Louis Bossart wrote:
> You may want to run 'alsa-info' and provide a link to the uploaded
> results. It's hard to comment without any information on 'hardware
> configurations like mine'.
> Thanks.
Sorry, I thought the output of `aplay -l` would be enough. The results 
are here;
http://alsa-project.org/db/?f=bc64421df5181d1ba3bdf157c40d06dd52a7224b

~ Eldred

Re: Dual simulatenous output on single card not recognized

[Pierre-Louis Bossart]

On 11/30/21 1:44 AM, Eldred HABERT wrote:
> 
> On 29/11/2021 19:18, Pierre-Louis Bossart wrote:
>> You may want to run 'alsa-info' and provide a link to the uploaded
>> results. It's hard to comment without any information on 'hardware
>> configurations like mine'.
>> Thanks.
> Sorry, I thought the output of `aplay -l` would be enough. The results
> are here;
> http://alsa-project.org/db/?f=bc64421df5181d1ba3bdf157c40d06dd52a7224b

ok, so you have a CNL-H chipset and no digital mics, so the legacy
HDaudio driver is used (not SOF w/ the DSP enabled).

There's nothing at the driver level that would prevent the use of
independent outputs, such as built-in speakers and HDMI concurrently.
You can verify this assertion by opening different terminals and trying

speaker-test -Dhw:0,0 -c2 -r48000

speaker-test -Dhw:0,3 -c2 -r48000 (use 0,7 8 9 10 as needed, depending
on which device is tagged as connected to a valid HDMI output in the
mixer 'Jack' status)

I am not sure though how the Gnome settings would let you do this. This
seems like a user-space problem to me?