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  1. 20 5月, 2012 3 次提交
  3. 14 5月, 2012 2 次提交
    • S
      [media] s5p-fimc: Fix locking in subdev set_crop op · 5be4fe63
      由 Sylwester Nawrocki 提交于 
      When setting TRY crop on the sub-device the mutex was erroneously acquired
rather than released on exit path. This bug is present in kernels starting
from v3.2.

Cc: stable@vger.kernel.org
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      5be4fe63
    • H
      [media] v4l2-dev: add flag to have the core lock all file operations · 5126f259
      由 Hans Verkuil 提交于 
      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: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      5126f259
  5. 08 5月, 2012 2 次提交
  7. 11 4月, 2012 2 次提交
  9. 08 3月, 2012 2 次提交
  11. 18 1月, 2012 1 次提交
  13. 31 12月, 2011 1 次提交
    • S
      [media] s5p-fimc: Add support for alpha component configuration · dafb9c70
      由 Sylwester Nawrocki 提交于 
      On Exynos SoCs the FIMC IP allows to configure globally the alpha
component of all pixels for V4L2_PIX_FMT_RGB32, V4L2_PIX_FMT_RGB555
and V4L2_PIX_FMT_RGB444 image formats. This patch adds a v4l2 control
in order to let the applications control the alpha component value.

The alpha value range depends on the pixel format, for RGB32 it's
0..255 (8-bits), for RGB555 - 0..1 (1-bit) and for RGB444 - 0..15
(4-bits). The v4l2 control range is always 0..255 and the alpha
component data width is determined by currently set format on the
V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE buffer queue. The applications
need to match the alpha channel value range and the pixel format
since the driver will clamp the alpha component. Depending on
fourcc the valid alpha bits are:

 - V4L2_PIX_FMT_RGB555  [0]
 - V4L2_PIX_FMT_RGB444  [3:0]
 - V4L2_PIX_FMT_RGB32   [7:0]

When switching to a pixel format with smaller alpha component width
the currently set alpha value will be clamped to maximum value valid
for current format. When switching to a format with wider alpha the
alpha value remains unchanged.

The variant description data structure is extended with a new entry
so an additional control is created only where really supported by
the hardware.

V4L2_PIX_FMT_RGB555 and V4L2_PIX_FMT_RGB444 formats are only valid
for V4L2_BUF_TYPE_VIDEO_CAPTURE buffer queue.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      dafb9c70
  15. 11 12月, 2011 1 次提交
  17. 25 11月, 2011 3 次提交
  19. 04 11月, 2011 1 次提交
  21. 07 9月, 2011 20 次提交
  23. 28 7月, 2011 1 次提交
  25. 11 6月, 2011 1 次提交