- SWAPLR quirk for (unknown, luckily it is mine) broken uaudio stick.
Fixing by rewiring is impossible without damaging it. Luckily,
we can fix it using "other" methods :) .
- Add uaudio_get_vendor(), _product() and _release() in uaudio.c
(currently used by uaudio_pcm quirk).
- Implement CHANNEL_SETFRAGMENTS().
- Drop channel locking in few places where it is about to sleep
somewhere. This should help eliminating illegal locking acquisition
where the current thread is about to sleep, and also few deadlock
cases. Dropping it right here is quite safe since it is already
protected by CHN_F_BUSY flag and other threads won't bother to touch it.
Solving other illegal locking issues are quite tricky without converting
most usbd_do_request() calls to its equivalent _async() calls,
which I intend to do it later after getting full test report from
other people with different uaudio hardwares.
- Fix memory leak issues during detach. This seems common to any drivers
(notably emu10kx, csapcm?) with bridge functions.
It may be the case that you may hear some unwanted noise while
playing back with 24/32 bit. This is a problem in the USB system.
Explanation from Hans Petter Selasky:
---snip---
The current USB sound driver only uses one isochronous
buffer, that is restarted when it is completed. This will lead to a short
period of time, +1ms, where no sound data is sent to the external USB device.
Depending on the load of your computer, this can be as much as 50ms. So the
USB sound driver must use 2 isochronous transfers. At the beginning one will
queue both. Then these are restarted on completion. This will result in a
constant-rate data stream to the external sound device, a minimum sound
buffer equal to the size of the isochronous buffer, and possibly the sound
will reach your ears with less delay. Little delay is a result of constant
data rate. Currently only my USB driver will support that. If one tries that
with the USB driver in *BSD, then it will crash at the first moment one gets
a buffer underrun.
---snip---
Submitted by: Kazuhito HONDA <kazuhito@ph.noda.tus.ac.jp>
Mono-recording still not tested by: julian
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
