Commit Graph

15 Commits

Author SHA1 Message Date
Adrian Bunk 3f84307a10 V4L/DVB (6803): buf-core.c locking fixes
After commit 19fb145799 the callers in
videobuf-core.c that already hold the lock must call
__videobuf_read_start() instead of videobuf_read_start().

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-12-13 00:15:25 -02:00
Mauro Carvalho Chehab 19fb145799 V4L/DVB (6609): Re-adds lock safe videobuf_read_start
videobuf_dvb needs videobuf_read_start. The EXPORT_SYMBOL_GPL() were removed by
a previous patch. However, videobuf_dvb needs this.

This patch re-adds videobuf_read_start, doing the proper lock.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-12-12 08:21:37 -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
Pekka Enberg a13625c518 V4L/DVB (6324): fix videobuf_cgmbuf export
As videobuf_cgmbuf is defined only if CONFIG_VIDEO_V4L1_COMPAT is enabled,
move the EXPORT_SYMBOL_GPL declaration inside the #ifdef block.  Fixes
compilation for x86_64 defconfig.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-10-22 12:01:35 -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
Trent Piepho a991f44b79 V4L/DVB (6316): Change list_for_each+list_entry to list_for_each_entry
The rest of V4L files.

There is one list_for_each+list_entry in cpia_pp.c that
wasn't changed because it expects the loop iterator to remain NULL if
the list is empty.

A bug in vivi is fixed; the 'safe' version needs to be used because the loop
deletes the list entries.

Simplify a second loop in vivi and get rid if an un-used variable in that loop.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-10-10 13:35:29 -03:00
Brandon Philips 49ee718ef5 V4L/DVB (6305): V4L: videobuf-core.c avoid NULL dereferences in videobuf-core
The return value of videobuf_alloc() is unchecked but this function will
return NULL on an error.  Check for NULL and make videobuf_reqbufs()
return the number of successfully allocated buffers.

Also, fix saa7146_video.c and bttv-driver.c to use this returned
buffer count.

Tested against the vivi driver.  Not tested against saa7146 or bt8xx
devices.

Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-10-10 00:03:20 -03:00
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 d5f1b01644 V4L/DVB (6291): Fix: avoid oops on some SMP machines
This workaround fix a bug that happens on some SMP machines. On those machines,
videobuf_iolock is called too soon, before file .mmap handler. This patch calls
the scheduler before iolocking, allowing it to properly call the pending mmap.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-10-10 00:03:14 -03:00
Maxim Levitsky d00cd2985e V4L/DVB (6278): Buf: fix typo that caused data loss when readng streams from device
If videobuf_read_stream reads two or more buffers it was overwriting the first one

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
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 00:03:08 -03:00
Brandon Philips 00f98d0804 V4L/DVB (6276): V4L: videobuf-core.c lock before streaming check
The reading/streaming fields are used for mutual exclusion of the queue and
should be protected by the queue lock.

Signed-off-by: Brandon Philips <bphilips@suse.de>
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 00:03:05 -03:00
Maxim Levitsky 9900132f34 V4L/DVB (6268): V4L: Fix a lock inversion in generic videobuf code
videobuf_qbuf takes q->lock, and then calls
q->ops->buf_prepare which by design in all drivers calls
videobuf_iolock which calls videobuf_dma_init_user and this
takes current->mm->mmap_sem

on the other hand if user calls mumap from other thread, sys_munmap
takes current->mm->mmap_sem and videobuf_vm_close takes q->lock

Since this can occur only for V4L2_MEMORY_MMAP buffers, take
current->mm->mmap_sem in qbuf, before q->lock, and don't take
current->mm->mmap_sem videobuf_dma_init_user for those buffers

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
http://thread.gmane.org/gmane.comp.video.video4linux/34978/focus=34981
Reviewed-by: Ricardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-10-10 00:02:58 -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 cd4765efdd V4L/DVB (6265): Prevent for calling mmap_free without an allocated buffer
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