Hi Daniel,
On Thu, 15 Nov 2012, Daniel Griscom wrote:
I'm having trouble getting implicit feedback working with my custom capture/playback USB audio class device, even with the latest kernel. I presume it's a problem with my device's configuration, but can't figure out exactly what the problem is (after a whole lotta investigation).
What exactly doesn't work? The "lsusb -v" output from your device might help here.
Is there any commercial USB hardware out there that supports implicit feedback? I assume the ALSA developers are testing against something, but I can't find anything appropriate.
I'm not an ALSA dev, but I recently posted a series of patches for the M-Audio Fast Track C400, which uses the implicit feedback code that was already in the tree for other devices. Take a look at sound/usb/pcm.c, there are quite a few hints to how this is discovered currently.
Cheers, Eldad