Commit 67ec1072b0 ("ALSA: pcm: Fix rwsem deadlock for non-atomic PCM
stream") fixes deadlock for non-atomic PCM stream. But, This patch
causes antother stuck.
If writer is RT thread and reader is a normal thread, the reader
thread will be difficult to get scheduled. It may not give chance to
release readlocks and writer gets stuck for a long time if they are
pinned to single cpu.
The deadlock described in the previous commit is because the linux
rwsem queues like a FIFO. So, we might need non-FIFO writelock, not
non-block one.
My suggestion is that the writer gives reader a chance to be scheduled
by using the minimum msleep() instaed of spinning without blocking by
writer. Also, The *_nonblock may be changed to *_nonfifo appropriately
to this concept.
In terms of performance, when trylock is failed, this minimum periodic
msleep will have the same performance as the tick-based
schedule()/wake_up_q().
[ Although this has a fairly high performance penalty, the relevant
code path became already rare due to the previous commit ("ALSA:
pcm: Call snd_pcm_unlink() conditionally at closing"). That is, now
this unconditional msleep appears only when using linked streams,
and this must be a rare case. So we accept this as a quick
workaround until finding a more suitable one -- tiwai ]
Fixes: 67ec1072b0 ("ALSA: pcm: Fix rwsem deadlock for non-atomic PCM stream")
Suggested-by: Wonmin Jung <wonmin.jung@lge.com>
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Currently the PCM core calls snd_pcm_unlink() always unconditionally
at closing a stream. However, since snd_pcm_unlink() invokes the
global rwsem down, the lock can be easily contended. More badly, when
a thread runs in a high priority RT-FIFO, it may stall at spinning.
Basically the call of snd_pcm_unlink() is required only for the linked
streams that are already rare occasion. For normal use cases, this
code path is fairly superfluous.
As an optimization (and also as a workaround for the RT problem
above in normal situations without linked streams), this patch adds a
check before calling snd_pcm_unlink() and calls it only when needed.
Reported-by: Chanho Min <chanho.min@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Basically the xrun injection routine can simply call the standard
helper snd_pcm_stop_xrun(), but with one exception: it may be called
even when the stream is closed.
Make snd_pcm_stop_xrun() more robust and check the NULL runtime state,
and simplify xrun injection code by calling it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The PCM xrun injection triggers directly snd_pcm_stop() without the
standard xrun handler, hence it's not recorded on the event buffer.
Ditto for snd_pcm_stop_xrun() call and SNDRV_PCM_IOCTL_XRUN ioctl.
They are inconvenient from the debugging POV.
Let's make them to trigger XRUN via the standard helper more
consistently.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The snd_pcm_stream_lock_irq*() functions decouple disabling interrupts
from the actual locking process. This does not work as expected if the
locking primitives are replaced like on preempt-rt.
Provide one function for locking which uses correct locking primitives.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.
Commit 1c8f422059 ("mm: change return type to vm_fault_t")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
It looks like a simple mistake that this struct member
was forgotten.
Audio_tstamp isn't used much, and on some archs (such as x86) this
ioctl is not used by default, so that might be the reason why this
has slipped for so long.
Fixes: 4eeaaeaea1 ("ALSA: core: add hooks for audio timestamps")
Signed-off-by: David Henningsson <diwic@ubuntu.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org> # v3.8+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The commit c2c86a9717 ("ALSA: pcm: Remove set_fs() in PCM core code")
changed SNDRV_PCM_IOCTL_DELAY to return an inconsistent error instead of a
negative delay. Originally the call would succeed and return the negative
delay. The Chromium OS Audio Server (CRAS) gets confused and hangs when
the error is returned instead of the negative delay.
Help CRAS avoid the issue by rolling back the behavior to return a
negative delay instead of an error.
Fixes: c2c86a9717 ("ALSA: pcm: Remove set_fs() in PCM core code")
Signed-off-by: Jeffery Miller <jmiller@neverware.com>
Cc: <stable@vger.kernel.org> # v4.13+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Yet another slight code cleanup: there are two places where
calculating the PCM delay, and they can be unified in a single
helper. It reduces the multiple open codes.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The poll callbacks for playback and capture directions are doing
fairly similar but with a slight difference. This patch unifies the
two functions into a single callback. The advantage of this
refactoring is that the direction-specific procedures become clearer.
There should be no functional change but only the code cleanup.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Introduce two new direction-neutral helpers to calculate the avail and
hw_avail values, and clean up the code with them.
The two separated forward and rewind functions are gathered to the
unified functions.
No functional change but only code reductions.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
snd_pcm_hw_params() (more exactly snd_pcm_hw_params_choose()) contains
a check of the return error from snd_pcm_hw_param_first() and _last()
with snd_BUG_ON() -- i.e. it may trigger WARN_ON() depending on the
kconfig.
This was a valid check in the past, as these functions shouldn't
return any error if the parameters have been already refined via
snd_pcm_hw_refine() beforehand. However, the recent rewrite
introduced a kmalloc() in snd_pcm_hw_refine() for removing VLA, and
this brought a possibility to trigger an error. As a result, syzbot
caught lots of superfluous kernel WARN_ON() and paniced via fault
injection.
As the WARN_ON() is no longer valid with the introduction of
kmalloc(), let's drop snd_BUG_ON() check, in order to make the world
peaceful place again.
Reported-by: syzbot+803e0047ac3a3096bb4f@syzkaller.appspotmail.com
Fixes: 5730f9f744 ("ALSA: pcm: Remove VLA usage")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When trying to use the driver (e.g. aplay *.wav), the 4MiB DMA buffer
will get mmapp'ed in 16KiB chunks. But this fails with the 2nd 16KiB
area, as the page offset is outside of the VMA range (size), which is
currently used as size parameter in snd_pcm_lib_default_mmap(). By
using the DMA buffer size (dma_bytes) instead, the complete DMA buffer
can be mmapp'ed and the issue is fixed.
This issue was detected on an ARM platform (TI AM57xx) using the RME
HDSP MADI PCIe soundcard.
Fixes: 657b1989da ("ALSA: pcm - Use dma_mmap_coherent() if available")
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A helper function used by snd_pcm_hw_refine() still keeps using VLA
for timestamps of hw constraint rules that are non-fixed size.
Let's replace the VLA with a simple kmalloc() array.
Reference: https://lkml.org/lkml/2018/3/7/621
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull poll annotations from Al Viro:
"This introduces a __bitwise type for POLL### bitmap, and propagates
the annotations through the tree. Most of that stuff is as simple as
'make ->poll() instances return __poll_t and do the same to local
variables used to hold the future return value'.
Some of the obvious brainos found in process are fixed (e.g. POLLIN
misspelled as POLL_IN). At that point the amount of sparse warnings is
low and most of them are for genuine bugs - e.g. ->poll() instance
deciding to return -EINVAL instead of a bitmap. I hadn't touched those
in this series - it's large enough as it is.
Another problem it has caught was eventpoll() ABI mess; select.c and
eventpoll.c assumed that corresponding POLL### and EPOLL### were
equal. That's true for some, but not all of them - EPOLL### are
arch-independent, but POLL### are not.
The last commit in this series separates userland POLL### values from
the (now arch-independent) kernel-side ones, converting between them
in the few places where they are copied to/from userland. AFAICS, this
is the least disruptive fix preserving poll(2) ABI and making epoll()
work on all architectures.
As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
it will trigger only on what would've triggered EPOLLWRBAND on other
architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
at all on sparc. With this patch they should work consistently on all
architectures"
* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
make kernel-side POLL... arch-independent
eventpoll: no need to mask the result of epi_item_poll() again
eventpoll: constify struct epoll_event pointers
debugging printk in sg_poll() uses %x to print POLL... bitmap
annotate poll(2) guts
9p: untangle ->poll() mess
->si_band gets POLL... bitmap stored into a user-visible long field
ring_buffer_poll_wait() return value used as return value of ->poll()
the rest of drivers/*: annotate ->poll() instances
media: annotate ->poll() instances
fs: annotate ->poll() instances
ipc, kernel, mm: annotate ->poll() instances
net: annotate ->poll() instances
apparmor: annotate ->poll() instances
tomoyo: annotate ->poll() instances
sound: annotate ->poll() instances
acpi: annotate ->poll() instances
crypto: annotate ->poll() instances
block: annotate ->poll() instances
x86: annotate ->poll() instances
...
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.
Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The commit 9027c4639e ("ALSA: pcm: Call ack() whenever appl_ptr is
updated") introduced the possible error code returned from the PCM
rewind ioctl. Basically the change was for handling the indirect PCM
more correctly, but ironically, it caused rather a side-effect:
PulseAudio gets pissed off when receiving an error from rewind, throws
everything away and stops processing further, resulting in the
silence.
It's clearly a failure in the application side, so the best would be
to fix that bug in PA. OTOH, PA is mostly the only user of the rewind
feature, so it's not good to slap the sole customer.
This patch tries to mitigate the situation: instead of returning an
error, now the rewind ioctl returns zero when the driver can't rewind.
It indicates that no rewind was performed, so the behavior is
consistent, at least.
Fixes: 9027c4639e ("ALSA: pcm: Call ack() whenever appl_ptr is updated")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
An earlier commit removed the access to variable runtime
and we are now left with unused variable that is redundant,
so remove it.
Cleans up the clang warning: Value stored to 'runtime' is never read
Fixes: e11f0f90a6 ("ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Some ioctl functions are implemented individually for both playback
and capture streams although most of the codes are identical with just
a few different stream-specific function calls. This patch unifies
these places, removes the superfluous trivial check and flattens the
call paths as a cleanup. Meanwhile, for better readability, some
codes (e.g. xfer ioctls or forward/rewind ioctls) are factored out as
functions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Currently we're taking power_lock at each card component for assuring
the power-up sequence, but it doesn't help anything in the
implementation at the moment: it just serializes unnecessarily the
callers, but it doesn't protect about the power state change itself.
It used to have some usefulness in the early days where we managed the
PM manually. But now the suspend/resume core procedure is beyond our
hands, and power_lock lost its meaning.
This patch drops the power_lock from allover the places.
There shouldn't be any issues by this change, as it's no helper
regarding the power state change. Rather we'll get better performance
by removing the serialization; which is the only slight concern of any
behavior change, but it can't be a showstopper, after all.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Chanho Min
Takashi Iwai
Kees Cook
Anna-Maria Gleixner
Souptick Joarder
David Henningsson
Jeffery Miller
Stefan Roese
Linus Torvalds
Luis de Bethencourt
Al Viro
Colin Ian King