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