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| author | Sergey Senozhatsky <senozhatsky@chromium.org> | 2020-05-14 18:01:43 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-06-23 13:28:17 +0200 |
| commit | ac53503ee38a1ffbc47c7cca6cbfc48ba9c65c5e (patch) | |
| tree | b7ecc13ff0ade9fd511d5f7a788237cb0f126a00 /Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst | |
| parent | f5f5fa73fbfb9f346f1b5f37ebf343bae6ef6361 (diff) | |
media: videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag
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>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst index b6d52083707b..96a59793d857 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst @@ -126,6 +126,7 @@ aborting or finishing any DMA in progress, an implicit .. _V4L2-BUF-CAP-SUPPORTS-REQUESTS: .. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS: .. _V4L2-BUF-CAP-SUPPORTS-M2M-HOLD-CAPTURE-BUF: +.. _V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS: .. cssclass:: longtable @@ -156,6 +157,15 @@ aborting or finishing any DMA in progress, an implicit - Only valid for stateless decoders. If set, then userspace can set the ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag to hold off on returning the capture buffer until the OUTPUT timestamp changes. + * - ``V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS`` + - 0x00000040 + - This capability is set by the driver to indicate that the queue supports + cache and memory management hints. However, it's only valid when the + queue is used for :ref:`memory mapping <mmap>` streaming I/O. See + :ref:`V4L2_FLAG_MEMORY_NON_CONSISTENT <V4L2-FLAG-MEMORY-NON-CONSISTENT>`, + :ref:`V4L2_BUF_FLAG_NO_CACHE_INVALIDATE <V4L2-BUF-FLAG-NO-CACHE-INVALIDATE>` and + :ref:`V4L2_BUF_FLAG_NO_CACHE_CLEAN <V4L2-BUF-FLAG-NO-CACHE-CLEAN>`. + Return Value ============ |