2021-08-20
Since the sound drivers will have a couple of changes I am writing this note for the people of #asahi.
The ALSA card now has devices Primary
/hw:0,0
and Secondary
/hw:0,1
. Routing of audio from the devices to speakers/headphones depends on the state of the card's controls (those seen in alsamixer). By default both headphones/speakers are routed to the primary device, with one or the other being enabled based on the plug state of the jack connector. You can override that. To drive all the speakers on large (>2ch) speaker arrays, you need to use the secondary device. So you set the Speaker Playback Mux
to Secondary
, then stream audio to hw:0,1
. This is because the primary device has some parameters set to appease the jack codec -- this limitation may be lifted in the future.
Anyway, such details should be hidden in proper userspace configuration, which we have yet to write.