vidiocgmbuf() does this:
mutex_lock(&fh->cap.vb_lock);
retval = videobuf_mmap_setup(&fh->cap, gbuffers, gbufsize,
V4L2_MEMORY_MMAP);
and videobuf_mmap_setup() then just does
mutex_lock(&q->vb_lock);
ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
mutex_unlock(&q->vb_lock);
which is an obvious double-take deadlock.
This patch fixes this by having vidiocgmbuf() just call the
__videobuf_mmap_setup function instead.
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Reported-by: Koos Vriezen <koos.vriezen@gmail.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
videobuf-dvb were still using a function that were videobuf-dma-sg
dependent. This patch creates a generic handler for this function. This
way, videobuf-dvb can now work with all videobuf implementations.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Add a waitqueue to wait on when there are no buffers in the buffer queue.
DQBUF waits on this queue without holding vb_lock to allow a QBUF to happen.
Once a buffer has been queued we recheck that the queue is still streaming and
wait on the new buffer's waitqueue while holding the vb_lock. The driver
should come along in a timely manner and put the buffer into its next state
finishing the DQBUF.
By implementing this waitqueue it also brings the videobuf DQBUF up to spec and
it now blocks on O_NONBLOCK even when no buffers have been queued via QBUF:
"By default VIDIOC_DQBUF blocks when no buffer is in the outgoing queue."
- V4L2 spec
Signed-off-by: Brandon Philips <bphilips@suse.de>
CC: Trent Piepho <xyzzy@speakeasy.org>
CC: Carl Karsten <carl@personnelware.com>
CC: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Make the dev member of the struct videobuf_queue of type "struct device *"
to avoid future problems. Also change the prototype of the
videobuf_queue_core_init() function.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
In order to videobuf_iolock to work, mmap_mapper should be called first.
Otherwise, an OOPS is generated.
On some cases, .mmap file handler used to took some time to be called. On those
situations, mmap_mmapper() were called after iolock.
This patch properly waits for mmap_mapper to be called, otherwise generating an
error.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
- Add comments to functions that require that caller hold q->lock
- Add __videobuf_mmap_free that doesn't hold q->lock for use within videobuf
- Add locking to videobuf_mmap_free
- Fix linux/drivers/media/common/saa7146_video.c which was holding lock around
videobuf_read_stop
- Add locking to functions that operate on a queue
- Add videobuf_stop to take care of stopping in both the read and stream case
TODO: bttv still has an unsafe call to videobuf_queue_is_busy
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Breaks on any target that has copy_to_user() defined as a non-trivial
macro.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the past, videobuf_queue_init were used to initialize PCI DMA videobuffers.
This patch renames it, to avoid confusion with the previous kernel API, doing:
s/videobuf_queue_init/void videobuf_queue_core_init/
Also, the operations is now part of the function parameter. The function will
also add a test if this is defined, otherwise producing BUG.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Before the videobuf redesign, a procedure for re-using videobuf without PCI
scatter/gather where provided by changing the pci-dependent operations by
other operations.
With the newer approach, those methods are obsolete and can safelly be removed.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
video-buf currently does two different tasks:
- Manages video buffers with a common code that allows
implementing all the V4L2 different modes of buffering;
- Controls memory allocations
While the first task is generic, the second were written to support PCI DMA
Scatter/Gather needs. The original approach can't even work for those
video capture hardware that don't support scatter/gather.
I did one approach to make it more generic. While the approach worked
fine for vivi driver, it were not generic enough to handle USB needs.
This patch creates two different modules, one containing the generic
video buffer handling (videobuf-core) and another with PCI DMA S/G.
After this patch, it would be simpler to write an USB video-buf and a
non-SG DMA module.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981
Reviewed-by: Ricardo Cerqueira <v4l@cerqueira.org>
Mauro Carvalho Chehab
Arjan van de Ven
Mauro Carvalho Chehab
Brandon Philips
Guennadi Liakhovetski
Al Viro