diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/buffer.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/buffer.rst | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst index e2c85ddc990b..2e266d32470a 100644 --- a/Documentation/media/uapi/v4l/buffer.rst +++ b/Documentation/media/uapi/v4l/buffer.rst @@ -306,10 +306,23 @@ struct v4l2_buffer - A place holder for future extensions. Drivers and applications must set this to 0. * - __u32 - - ``reserved`` + - ``request_fd`` - - - A place holder for future extensions. Drivers and applications - must set this to 0. + - The file descriptor of the request to queue the buffer to. If the flag + ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will be + queued to this request. If the flag is not set, then this field will + be ignored. + + The ``V4L2_BUF_FLAG_REQUEST_FD`` flag and this field are only used by + :ref:`ioctl VIDIOC_QBUF <VIDIOC_QBUF>` and ignored by other ioctls that + take a :c:type:`v4l2_buffer` as argument. + + Applications should not set ``V4L2_BUF_FLAG_REQUEST_FD`` for any ioctls + other than :ref:`VIDIOC_QBUF <VIDIOC_QBUF>`. + + If the device does not support requests, then ``EACCES`` will be returned. + If requests are supported but an invalid request file descriptor is + given, then ``EINVAL`` will be returned. @@ -514,6 +527,11 @@ Buffer Flags streaming may continue as normal and the buffer may be reused normally. Drivers set this flag when the ``VIDIOC_DQBUF`` ioctl is called. + * .. _`V4L2-BUF-FLAG-IN-REQUEST`: + + - ``V4L2_BUF_FLAG_IN_REQUEST`` + - 0x00000080 + - This buffer is part of a request that hasn't been queued yet. * .. _`V4L2-BUF-FLAG-KEYFRAME`: - ``V4L2_BUF_FLAG_KEYFRAME`` @@ -589,6 +607,11 @@ Buffer Flags the format. Any Any subsequent call to the :ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl will not block anymore, but return an ``EPIPE`` error code. + * .. _`V4L2-BUF-FLAG-REQUEST-FD`: + + - ``V4L2_BUF_FLAG_REQUEST_FD`` + - 0x00800000 + - The ``request_fd`` field contains a valid file descriptor. * .. _`V4L2-BUF-FLAG-TIMESTAMP-MASK`: - ``V4L2_BUF_FLAG_TIMESTAMP_MASK`` |