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Subject[PATCH] media: vidioc-queryctrl.rst: clarify combining READ_ONLY with WRITE_ONLY
Make it clear in the documentation that V4L2_CTRL_FLAG_READ_ONLY doesn't
conflict with V4L2_CTRL_FLAG_WRITE_ONLY. Also make it clear that
if both are combined then the control has read and write permissions.

Signed-off-by: Helen Koike <>


v4l2-compliance expects both flags for read and write permissions, so I
would like to make it clear in the docs.
Please let me know if this is not the case.

Documentation/media/uapi/v4l/vidioc-queryctrl.rst | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
index a3d56ffbf4cc..1d3aecdf679f 100644
--- a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
+++ b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
@@ -500,6 +500,11 @@ See also the examples in :ref:`control`.
- 0x0004
- This control is permanently readable only. Any attempt to change
the control will result in an ``EINVAL`` error code.
+ .. note::
+ If combined with ``V4L2_CTRL_FLAG_WRITE_ONLY``, then both, read
+ and write are allowed.
- 0x0008
- A hint that changing this control may affect the value of other
@@ -523,6 +528,11 @@ See also the examples in :ref:`control`.
where writing a value will cause the device to carry out a given
action (e. g. motor control) but no meaningful value can be
+ .. note::
+ If combined with ``V4L2_CTRL_FLAG_READ_ONLY``, then both, read
+ and write are allowed.
- 0x0080
- This control is volatile, which means that the value of the
 \ /
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