The documentation of the Memory Consistency Flags was part of the struct
v4l2_buffer documentation, but that struct doesn't use those flags. Instead
it is used by VIDIOC_CREATE_BUFS and VIDIOC_REQBUFS. Move the documentation
from buffer.rst to vidioc-reqbufs.rst which is where it belongs.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The documentation for V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS and
V4L2_BUF_CAP_SUPPORTS_REMOVE_BUFS was missing. Add this.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
VIDIOC_REMOVE_BUFS ioctl allows to remove buffers from a queue.
The number of buffers to remove in given by count field of
struct v4l2_remove_buffers and the range start at the index
specified in the same structure.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil: vidioc-remove-bufs.rst: mention no bufs are freed on error]
Use one of the struct v4l2_create_buffers reserved bytes to report
the maximum possible number of buffers for the queue.
V4l2 framework set V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS flags in queue
capabilities so userland can know when the field is valid.
Does the same change in v4l2_create_buffers32 structure.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This patch lets user-space request a non-coherent memory
allocation during CREATE_BUFS and REQBUFS ioctl calls.
= CREATE_BUFS
struct v4l2_create_buffers has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= CREATE_BUFS32
struct v4l2_create_buffers32 has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= REQBUFS
We use one byte of a 4 byte ->reserved[1] member of struct
v4l2_requestbuffers. The struct, thus, now has reserved 3 bytes.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
By setting or clearing the V4L2_MEMORY_FLAG_NON_COHERENT flag
user-space should be able to hint vb2 that either non-coherent
(if supported) or coherent memory should be used for the buffer
allocation.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
There are lots of tables that are not properly displayed
in LaTeX/PDF.
Fix the tablecolumns, add longtable where needed and LaTeX
formatting macros, in order to address such issues.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Sphinx 3.x broke support for the cdomain.py extension, as the
c domain code was rewritten. Due to that, the c tags need to
be re-written, in order to use the new c domain notation.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The patch partially reverts some of the UAPI bits of the buffer
cache management hints. Namely, the queue consistency (memory
coherency) user-space hint because, as it turned out, the kernel
implementation of this feature was misusing DMA_ATTR_NON_CONSISTENT.
The patch reverts both kernel and user space parts: removes the
DMA consistency attr functions, rolls back changes to v4l2_requestbuffers,
v4l2_create_buffers structures and corresponding UAPI functions
(plus compat32 layer) and cleans up the documentation.
[hverkuil: fixed a few typos in the commit log]
[hverkuil: fixed vb2_core_reqbufs call in drivers/media/dvb-core/dvb_vb2.c]
[mchehab: fixed a typo in the commit log: revers->reverts]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
SPDX v3.10 gained support for GFDL-1.1 with no invariant sections:
https://spdx.org/licenses/GFDL-1.1-no-invariants-or-later.html
So, remove the license text, replacing them by this new SPDX
license.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This patch lets user-space to request a non-consistent memory
allocation during CREATE_BUFS and REQBUFS ioctl calls.
= CREATE_BUFS
struct v4l2_create_buffers has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= CREATE_BUFS32
struct v4l2_create_buffers32 has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= REQBUFS
We use one bit of a ->reserved[1] member of struct v4l2_requestbuffers,
which is now renamed to ->flags. Unlike v4l2_create_buffers, struct
v4l2_requestbuffers does not have enough reserved room. Therefore for
backward compatibility ->reserved and ->flags were put into anonymous
union.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
By setting or clearing V4L2_FLAG_MEMORY_NON_CONSISTENT flag
user-space should be able to set or clear queue's NON_CONSISTENT
->dma_attrs. Queue's ->dma_attrs are passed to the underlying
allocator in __vb2_buf_mem_alloc(), so thus user-space is able
to request vb2 buffer's memory to be either consistent (coherent)
or non-consistent.
The patch set also adds a corresponding capability flag:
fill_buf_caps() reports V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS
when queue supports user-space cache management hints. Note,
however, that MMAP_CACHE_HINTS capability only valid when the
queue is used for memory MMAP-ed streaming I/O.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
any others capabilities -> any other capabilities
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
