One of a set of patches submitted by Kazuhito HONDA
to make the usb audio driver a lot more capable.
PR: 75274
Submitted by: Kazuhito HONDA (kazuhito at ph dot noda dot tus dot ac dot jp)
Obtained from: NetBSD (indirectly)
MFC after: 2 weeks
This driver actually works slightly better on -stable than on -current
(the system locks on detach on -current), so it should be MFC'd somewhat
sooner.
This driver currently points out a difficulty in the sound device framework.
The PCM unregister routine is allowed to refuse the detach if the device is
in use. In the case of a USB device, however, this unregistration is much more
mandatory in nature, since the device is *actually* gone when this call is
made. The sound subsystem really should not refuse an unregistration and
should take its own steps to reject further I/O. As a result, if you detach
a USB sound device while it is in use, you can expect a panic shortly
thereafter.
This device cannot currently record audio. Some routines are unwritten as
of yet in uaudio.c to support recording.
This device hangs my -current box on detach. I don't know why. This does
not happen on my -stable machine.
Obtained from: Hiroyuki Aizu
MFC after: 2 weeks
