On Tue, 19 Jan 2021 18:40:04 +0100, Mike Oliphant wrote:
Your mixer.c patch does get rid of the RANGE errors. No change to behavior, though.
I'd already tried setting "implicit_fb=1" even though I didn't expect it to work, since there is a separate feedback endpoint. I just tried it again - it doesn't seem to hurt anything, but it doesn't help either.
Capture seems to be working perfectly with the clock patch - I'm not sure why I was initially getting noisy input.
I checked "/proc/asound/card*/pcm*/sub*/status" during playback, and the pointer seems to be moving forward as it should. All indications are that the system thinks playback is working fine.
One interesting piece of information - alsamixer shows two stereo outputs ("pcm" and "pcm1"). Not sure why there are two - maybe output is going to the wrong one?
You might need to unmute and increase both. The first one should be a master volume/switch while the second one is for the stereo channels.
Naming the mixer elements properly for USB-audio is a really tough task. Many firmware don't set the right strings and a guess work doesn't fit to all. But certainly there are some rooms for improvements there.
Takashi