Linux kernel stable tree https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=master 2012-08-15T19:43:09+00:00 2012-08-15T19:43:09+00:00 Mauro Carvalho Chehab mchehab@redhat.com 2012-08-14T20:31:16+00:00 urn:sha1:2c3fb08b3f74b8792004095a1f6881a3296ff643 The remaining drivers are mostly platform drivers. Name the dir to reflect it. It makes sense to latter break it into a few other dirs. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 2012-08-09T23:11:15+00:00 Hans Verkuil hans.verkuil@cisco.com 2012-06-24T09:36:49+00:00 urn:sha1:28c3682ac59dcc551682eceb021b66386ee4e570 Add proper locking to the file operations, allowing for the removal of the V4L2_FL_LOCK_ALL_FOPS flag. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 2012-05-14T12:19:38+00:00 Hans Verkuil hans.verkuil@cisco.com 2012-05-10T07:57:22+00:00 urn:sha1:5126f2590bee412e3053de851cb07f531e4be36a This used to be the default if the lock pointer was set, but now that lock is by default only used for ioctl serialization. Those drivers that already used core locking have this flag set explicitly, except for some drivers where it was obvious that there was no need to serialize any file operations other than ioctl. The drivers that didn't need this flag were: drivers/media/radio/dsbr100.c drivers/media/radio/radio-isa.c drivers/media/radio/radio-keene.c drivers/media/radio/radio-miropcm20.c drivers/media/radio/radio-mr800.c drivers/media/radio/radio-tea5764.c drivers/media/radio/radio-timb.c drivers/media/video/vivi.c sound/i2c/other/tea575x-tuner.c The other drivers that use core locking and where it was not immediately obvious that this flag wasn't needed were changed so that the flag is set together with a comment that that driver needs work to avoid having to set that flag. This will often involve taking the core lock in the fops themselves. Eventually this flag should go and it should not be used in new drivers. There are a few reasons why we want to avoid core locking of non-ioctl fops: in the case of mmap this can lead to a deadlock in rare situations since when mmap is called the mmap_sem is held and it is possible for other parts of the code to take that lock as well (copy_from_user()/copy_to_user() perform a down_read(&mm->mmap_sem) when a page fault occurs). It is very unlikely that that happens since the core lock serializes all fops, but the kernel warns about it if lock validation is turned on. For poll it is also undesirable to take the core lock as that can introduce increased latency. The same is true for read/write. While it was possible to make flags or something to turn on/off taking the core lock for each file operation, in practice it is much simpler to just not take it at all except for ioctl and leave it to the driver to take the lock. There are only a handful fops compared to the zillion ioctls we have. I also wanted to make it obvious which drivers still take the lock for all fops, so that's why I chose to have drivers set it explicitly. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> 2012-03-19T18:08:20+00:00 Scott Jiang scott.jiang.linux@gmail.com 2012-03-08T20:44:17+00:00 urn:sha1:63b1a90da93e019adcafa2b2b1b921fc97debec5 This is a v4l2 bridge driver for Blackfin video capture device, support ppi and eppi interface. Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>