previous commit:
Include <sys/mutex.h> and its prerequisite <sys/lock.h> instead of
depending on namespace pollution in <sys/buf.h>. Only do this in the
__FreeBSD_version > 500000 case although the __FreeBSD_version < 500000
case has already rotted.
Attempt to determine what function of AUX_OUT is: "True line level
out", "Headphone out", or "4-Channel out" and frig OSS mixer label
accordingly.
Addresses problem raised by Randy Bush on -multimedia of not being
able to hear audio on ich2 m/b which was eventually found to be
because the mixer monitor value was 0. On this h/w the label
"monitor" should now be presented as the marginally more intuitive
"ogain".
opening the device, eg one read only and one write only, and the
reference count being non-zero when both exit rendering device
permanently busy.
PR: kern/35004
Submitted by: Bill Wells
MFC after: 3 days
has been specified through /boot/loader.conf as opposed to setting it
in /etc/sysctl.conf. Only PCMDIR_PLAY channel can be used as a parent
of virtual channel. Do not initialize a new vchan for a given physical
channel if other physical channel already has one created.
PR: 31597
Approved by: obrien (mentor)
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.
Tested on: i386, alpha, sparc64
Problem:
selwakeup required calling pfind which would cause lock order
reversals with the allproc_lock and the per-process filedesc lock.
Solution:
Instead of recording the pid of the select()'ing process into the
selinfo structure, actually record a pointer to the thread. To
avoid dereferencing a bad address all the selinfo structures that
are in use by a thread are kept in a list hung off the thread
(protected by sellock). When a selwakeup occurs the selinfo is
removed from that threads list, it is also removed on the way out
of select or poll where the thread will traverse its list removing
all the selinfos from its own list.
Problem:
Previously the PROC_LOCK was used to provide the mutual exclusion
needed to ensure proper locking, this couldn't work because there
was a single condvar used for select and poll and condvars can
only be used with a single mutex.
Solution:
Introduce a global mutex 'sellock' which is used to provide mutual
exclusion when recording events to wait on as well as performing
notification when an event occurs.
Interesting note:
schedlock is required to manipulate the per-thread TDF_SELECT
flag, however if given its own field it would not need schedlock,
also because TDF_SELECT is only manipulated under sellock one
doesn't actually use schedlock for syncronization, only to protect
against corruption.
Proc locks are no longer used in select/poll.
Portions contributed by: davidc
AIOGCAP ioctl reports software-emulated formats. It defaults to on. People
who use performance-sensitive audio software and do not want it to pick a
software-emulated audio format instead of one supported by their hardware
should turn it off.
This unbreaks isdnphone(1) on systems with PCM-only sound cards.
Approved by: cg
* be more specific in verbose boot messages
* allow the feeder subsystem to veto pcm* attaching if there is an error
initialising the root feeder
* don't free/malloc a new tmpbuf when resizing a snd_dbuf to the same size as
it currently is
* store the feeder description in the feeder structure instead of mallocing
space for it
extensively as none of my testboxes have speakers or an audio source at
present, but the chains built look correct and reading /dev/audio (ulaw,
translated from signed 16 bit little-endian) gives values within the
expected range for silence.
default format for the chosen subdevice cannot be obtained return an error
instead of returning success with an indeteterminate format selected.
note that this should never happen once the feederchain builder works for
recording.
pcm0: ac97 codec failed to reset extended mode (0, got 80)
This was due to not masking off the correct extended function bits
in the read value from the extended status reg.
MFC after: 2 days
