Commit Graph

14 Commits

Author SHA1 Message Date
Arjan van de Ven
81b2dbcad8 Fix a deadlock in the bttv driver
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>
2008-05-20 10:12:26 -07:00
Mauro Carvalho Chehab
59d3448995 V4L/DVB (7566): videobuf-dvb: allow its usage with videobuf-vmalloc
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>
2008-04-24 14:09:39 -03:00
Brandon Philips
137d1cb19d V4L/DVB (7493): videobuf: Avoid deadlock with QBUF and bring up to spec for empty queue
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>
2008-04-24 14:07:57 -03:00
Guennadi Liakhovetski
e9bcf6675d V4L/DVB (7376): Improve compile-time type-checking in videobuf
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>
2008-04-24 14:07:51 -03:00
Mauro Carvalho Chehab
64f9477f95 V4L/DVB (7121): Renames videobuf lock to vb_lock
This helps to identify where vb_lock is being used, and find missusages of the
locks.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-02-18 11:15:12 -03:00
Mauro Carvalho Chehab
d05051c82e V4L/DVB (6997): Replace a very dirty hack on videobuf for a clean wait_event
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>
2008-01-25 19:04:46 -02:00
Brandon Philips
d6964aa8d4 V4L/DVB (6603): V4L: videobuf: convert streaming and reading to bitfields
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-01-25 19:02:11 -02:00
Brandon Philips
0fc0686e64 V4L/DVB (6600): V4L: videobuf: don't chew up namespace STATE_.*, convert to VIDEOBUF_
s/STATE_NEEDS_INIT/VIDEOBUF_NEEDS_INIT/g
s/STATE_PREPARED/VIDEOBUF_PREPARED/g
s/STATE_QUEUED/VIDEOBUF_QUEUED/g
s/STATE_ACTIVE/VIDEOBUF_ACTIVE/g
s/STATE_DONE/VIDEOBUF_DONE/g
s/STATE_ERROR/VIDEOBUF_ERROR/g
s/STATE_IDLE/VIDEOBUF_IDLE/g

Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-01-25 19:02:11 -02:00
Brandon Philips
19bc5133da V4L/DVB (6601): V4L: videobuf-core locking fixes and comments
- 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>
2007-12-11 18:08:08 -02:00
Al Viro
13bcd5d0e2 v4l: copy_to_user() is not a good method name
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>
2007-10-13 09:58:59 -07:00
Mauro Carvalho Chehab
d4cae5a500 V4L/DVB (6292): videobuf_core init always require callback implementation
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>
2007-10-10 00:03:14 -03:00
Mauro Carvalho Chehab
5ddff43435 V4L/DVB (6290): remove videobuf_set_pci_ops
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>
2007-10-10 00:03:10 -03:00
Mauro Carvalho Chehab
851c0c96b2 V4L/DVB (6266): videobuf cleanup: mmap check is common to all videobuf. Make it at core
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>
2007-10-10 00:02:55 -03:00
Mauro Carvalho Chehab
7a7d9a89d0 V4L/DVB (6251): Replace video-buf to a more generic approach
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>
2007-10-09 22:14:55 -03:00