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.
designated initializers.
I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.
- change midi_attach() to omit the 'parent' arg (there are
only two callers of this and it is not used)
- change midisyn_attach() to midisyn_init(), so not needing a midi_softc,
and fix the midi_pcppi driver to set hw_if and hw_hdl directly in
its midi_softc before calling midi_attach()
- add a device_t to opl_softc structure, change opl drivers to store
the device 'self' in opl_softc and fix opl_attach() to use this
opl_softc->dev field directly rather than a field in an otherwise
unused midi_softc
- remove unnecessary midi_softc from opl and cms drivers (child device
provides that)
reviewed by mrg
pointer, so no need to store it in sc_dev. Further, remove
the sc_dev field entirely since it is easily confused with
the dev field, which is the 'self' device pointer. Fix the
comment.
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.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
- Add a lot of missing selinit() and seldestroy() calls.
- Merge selwakeup() and selnotify() calls into a single selnotify().
- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.
Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>
Specifically eap but no midi, which makes sense if you want sound,
and umidi but no midi, which makes little sense but shouldn't fail the
build.
Suggest changing the evbarm conf files containing umidi but #midi
to comment out umidi as well (even though this fix should let them build).
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@
mrg