On my testing #Librem5 running #Mobian I had obviously installed a workaround to get echo cancellation for calls by using #pulseaudio for audio. I had forgotten about it and after some update or hardware tinkering sound just didn't work anymore.

I found out that I knew not much about sound and while trying to understand how it is supposed to work I wrote some of my findings on the Librem5 community wiki.

I'd be thankful for corrections and additions to be able to move the page soon out of the work in progress section.