On Mon, Apr 24, 2017 at 01:04:12AM +0800, Michael W. Bombardieri wrote: > Hi, > > When I remove uaudio_drain() on my laptop the attach/detach still > seems to work as expected. > I did a test with two usb soundcards. Audio files were played & > recorded using aucat. > > * boot system (no audio device because I disabled azalia) > * attach device1 (Creative card) > * play wav file1 (reference file) > * detach device1 > * attach device2 (Yamaha card) > * play wav file1 > * record wav file2 > * detach device2 > * attach device2 > * play wav file2 > * detach device2 > * attach device1 > * play wav file2 > * detach device1 > > So far this has only been tested on amd64. Maybe it produces > issues for your uaudio device though. >
AFAICS this is correct. uaudio_drain() used to be the "drain" method, but the audio(4) layer doesn't use it anymore. IMO, it shouldn't be called by uaudio_detach(), the device is gone and there are no outstanding requests.
