[media] exynos-gsc: don't clear format when freeing buffers with REQBUFS(0)

Browse source

User-space applications can use the VIDIOC_REQBUFS ioctl to determine if a
memory mapped, user pointer or DMABUF based I/O is supported by a driver.

For example, GStreamer attempts to determine the I/O methods supported by
the driver by doing many VIDIOC_REQBUFS ioctl calls with different memory
types and count 0. And then the real VIDIOC_REQBUFS call with count == n
is be made to allocate the buffers. But for count 0, the driver not only
frees the buffers but also clears the format set before with VIDIOC_S_FMT.

This is a problem since STREAMON fails if a format isn't set but GStreamer
first sets a format and then tries to determine the supported I/O methods,
so the format will be cleared on REQBUFS(0), before the call to STREAMON.

To avoid this issue, only free the buffers on VIDIOC_REQBUFS(0) but don't
clear the format. Since is completely valid to set the format and then do
different calls to REQBUFS before a call to STREAMON.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

...

This commit is contained in:

Javier Martinez Canillas 2016-09-30 18:16:42 -03:00 • committed by Mauro Carvalho Chehab

parent def2cc8c40

commit daba4dfbd2

1 changed files with 1 additions and 7 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

drivers/media/platform/exynos-gsc/gsc-m2m.c

View file