queued_count variable was left untouched during the queue reinitialization
in __vb2_queue_cancel, what might lead to mismatch between the real number
of queued buffers and queued_count variable.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This reverts commit 31901a07.

Queue should be reinitialized on each REQBUFS() call even if the memory
access method and buffer count have not been changed. The user might have
changed the format and if we go the short path introduced in that commit,
the memory buffer will not be reallocated to fit with new format.

The previous patch was just over-engineered optimization, which just
introduced a bug to videobuf2.
Reported-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

q->memory entry is initialized to late, so if allocation of memory buffers
fails, the buffers might not be freed correctly (q->memory is tested in
__vb2_free_mem, which can be called before setting q->memory).
Reported-by: NKamil Debski <k.debski@samsung.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Videobuf2 core assumes that driver doesn't set any buffer flags.
This is correct for buffer state flags that videobuf2 manages,
but the other flags like V4L2_BUF_FLAG_{KEY,P,B}FRAME,
V4L2_BUF_FLAG_TIMECODE and V4L2_BUF_FLAG_INPUT should be passed from or to
the driver.
Reported-by: NJonghun Han <jonghun.han@samsung.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The videobuf2-dma-contig allocator returns an ERR_PTR() on failure, not
a NULL like all other allocators. Fix videobuf2-core to also correctly
recognise those failures.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Fix vb2 not handling return value from start_streaming() callback.
Signed-off-by: NPawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

poll() should be returning poll-specific error values, not E* errors.
Signed-off-by: NPawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NPawel Osciak <pawel@osciak.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

__vb2_queue_free function doesn't really return anything useful. This patch
removes support for the return value to simplify the code.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Return immediately if the target number of buffers is the same as
the current one and memory access type doesn't change.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This patch fixes 2 minor bugs in videobuf2 core:
1. Queue should be reallocated if one change the memory access
method without changing the number of buffers.
2. In case of REQBUFS(0), the request should not be passed to the
driver.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/videobuf2-core.c: In function ‘__vb2_perform_fileio’:
drivers/media/video/videobuf2-core.c:1638: warning: format ‘%ld’ expects type ‘long int’, but argument 4 has type ‘size_t’
drivers/media/video/videobuf2-core.c:1697: warning: format ‘%ld’ expects type ‘long int’, but argument 2 has type ‘size_t’
drivers/media/video/videobuf2-core.c:1703: warning: format ‘%ld’ expects type ‘long int’, but argument 2 has type ‘size_t’
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add a generic file io (read and write) emulator for videobuf2. It uses
MMAP memory type buffers and generic vb2 calls: req_bufs, qbuf and
dqbuf. Video date is being copied from mmap buffers to userspace with
standard copy_to_user() function. To add support for file io the driver
needs to provide an additional callback - read_setup or write_setup. It
should provide the default number of buffers used by emulator and flags.

With these flags one can detemine the style of read() or write()
emulation. By default 'streaming' style is used. With
VB2_FILEIO_READ_ONCE flag one can select 'one shot' mode for read()
emulator. With VB2_FILEIO_WRITE_IMMEDIATE flag one can select immediate
conversion of write calls to qbuf for write() emulator, so the vb2 will
not wait until each buffer is filled completely before queueing it to
the driver.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Reviewed-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Videobuf2 is a Video for Linux 2 API-compatible driver framework for
multimedia devices. It acts as an intermediate layer between userspace
applications and device drivers. It also provides low-level, modular
memory management functions for drivers.

Videobuf2 eases driver development, reduces drivers' code size and aids in
proper and consistent implementation of V4L2 API in drivers.

Videobuf2 memory management backend is fully modular. This allows custom
memory management routines for devices and platforms with non-standard
memory management requirements to be plugged in, without changing the
high-level buffer management functions and API.

The framework provides:
- implementations of streaming I/O V4L2 ioctls and file operations
- high-level video buffer, video queue and state management functions
- video buffer memory allocation and management
Signed-off-by: NPawel Osciak <p.osciak@samsung.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Reviewed-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>