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author | Ingo Molnar <mingo@kernel.org> | 2018-11-03 23:42:16 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-11-03 23:42:16 +0100 |
commit | 23a12ddee1ce28065b71f14ccc695b5a0c8a64ff (patch) | |
tree | cedaa1cde5b2557116e523c31552187804704093 /Documentation/media/uapi/v4l/vidioc-reqbufs.rst | |
parent | compat: Cleanup in_compat_syscall() callers (diff) | |
parent | objtool: Support GCC 9 cold subfunction naming scheme (diff) | |
download | linux-dev-23a12ddee1ce28065b71f14ccc695b5a0c8a64ff.tar.xz linux-dev-23a12ddee1ce28065b71f14ccc695b5a0c8a64ff.zip |
Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-reqbufs.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst index 316f52c8a310..d4bbbb0c60e8 100644 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst @@ -88,10 +88,50 @@ any DMA in progress, an implicit ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See :c:type:`v4l2_memory`. * - __u32 - - ``reserved``\ [2] + - ``capabilities`` + - Set by the driver. If 0, then the driver doesn't support + capabilities. In that case all you know is that the driver is + guaranteed to support ``V4L2_MEMORY_MMAP`` and *might* support + other :c:type:`v4l2_memory` types. It will not support any others + capabilities. + + If you want to query the capabilities with a minimum of side-effects, + then this can be called with ``count`` set to 0, ``memory`` set to + ``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will + free any previously allocated buffers, so this is typically something + that will be done at the start of the application. + * - __u32 + - ``reserved``\ [1] - A place holder for future extensions. Drivers and applications must set the array to zero. +.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}| + +.. _v4l2-buf-capabilities: +.. _V4L2-BUF-CAP-SUPPORTS-MMAP: +.. _V4L2-BUF-CAP-SUPPORTS-USERPTR: +.. _V4L2-BUF-CAP-SUPPORTS-DMABUF: +.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS: + +.. cssclass:: longtable + +.. flat-table:: V4L2 Buffer Capabilities Flags + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - ``V4L2_BUF_CAP_SUPPORTS_MMAP`` + - 0x00000001 + - This buffer type supports the ``V4L2_MEMORY_MMAP`` streaming mode. + * - ``V4L2_BUF_CAP_SUPPORTS_USERPTR`` + - 0x00000002 + - This buffer type supports the ``V4L2_MEMORY_USERPTR`` streaming mode. + * - ``V4L2_BUF_CAP_SUPPORTS_DMABUF`` + - 0x00000004 + - This buffer type supports the ``V4L2_MEMORY_DMABUF`` streaming mode. + * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS`` + - 0x00000008 + - This buffer type supports :ref:`requests <media-request-api>`. Return Value ============ |