midi specific:
- add reference counting for midi operations, and ensure that
detach waits for other threads to complete before tearing
down the device completely.
- in detach, halt midi callouts before destroying them
- re-check sc->dying after sleeping in midiread()
- in real_writebytes(), make sure we're open and not dying
- make sure we drop the interrupt lock before calling any code
that may want to check thread locks. this is now safe due to
the above changes.
sequencer specific:
- avoid caching the midi softc in the sequencer softc. instead,
every time we want to use it, look it up again and make sure
it still exists.
this fixes various crashes i've seen in the usb midi code when
detaching the umidi while it is active.
the original ad-audiomp branch notes:
Add MP locking to the audio drivers.
Making the audio drivers MP safe is necessary before efforts
can be made to make the VM system MP safe.
The are two locks per device instance, an ISR lock and
a character device lock. The ISR lock replaces calls to
splaudio()/splx(), and will be held across calls to device
methods which were called at splaudio() before (e.g.
trigger_output). The character device lock is held across
calls to nearly all of the methods, excluding some only
used for initialization, e.g. get_locks.
Welcome to 5.99.57.
Merge from chap-midi branch, after
~month for review
Comments by thorpej@ drochner@ and Alexandre Ratchov
Incorporated: points by thorpej@ drochner@; preliminary support for
a stats-collecting ioctl suggested by martin@ from comments by A.R.
PR kern/32441 kern/32442 kern/32567 kern/32588 kern/32694 kern/33590
kern/33614 and one instance of kern/32651
ok martin@
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
the /dev/rmidiN devices, or with a sequencer interface via /dev/music.
So far the only supported MIDI device is the MPU401 port on SoundBlaster
(and only on SB on isapnp, since we do not have locators with multiple
values yet).
