From: Hans Verkuil <hansv...@cisco.com>
Document that V4L2_BUF_FLAG_REQUEST_FD should only be used with
VIDIOC_QBUF and cleared otherwise.
Signed-off-by: Hans Verkuil <hansv...@cisco.com>
Reviewed-by: Tomasz Figa <tf...@chromium.org>
---
Documentation/media/uapi/v4l/buffer.rst | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Documentation/media/uapi/v4l/buffer.rst
b/Documentation/media/uapi/v4l/buffer.rst
index 35c2fadd10de..1865cd5b9d3c 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -312,6 +312,8 @@ struct v4l2_buffer
and flag ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will be
queued to that request. This is set by the user when calling
:ref:`ioctl VIDIOC_QBUF <VIDIOC_QBUF>` and ignored by other ioctls.
+ 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 ``EPERM`` will be
returned.
If requests are supported but an invalid request file descriptor is
given, then ``EINVAL`` will be returned.
--
2.18.0
