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authorSakari Ailus <sakari.ailus@linux.intel.com>2018-11-21 20:29:35 +0300
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-11-23 13:16:29 +0300
commit5f229dcabc4acfb4e233e7678569f0fb9ab9c469 (patch)
tree52363894f33e0e3a34a3e56607adff19b2f83345 /Documentation/media
parent482ac2aa36fe24abac85c55db9213effce018929 (diff)
downloadlinux-5f229dcabc4acfb4e233e7678569f0fb9ab9c469.tar.xz
media: v4l: uAPI doc: Changing frame interval won't change format
Document that changing the frame interval has no effect on frame size. While this was the assumption in the API, it was not documented as such. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'Documentation/media')
-rw-r--r--Documentation/media/uapi/v4l/vidioc-g-parm.rst3
-rw-r--r--Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst3
2 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-parm.rst b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
index e831fa5512f0..c31585a7701b 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-parm.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
@@ -42,6 +42,9 @@ side. This is especially useful when using the :ref:`read() <func-read>` or
:ref:`write() <func-write>`, which are not augmented by timestamps or sequence
counters, and to avoid unnecessary data copying.
+Changing the frame interval shall never change the format. Changing the
+format, on the other hand, may change the frame interval.
+
Further these ioctls can be used to determine the number of buffers used
internally by a driver in read/write mode. For implications see the
section discussing the :ref:`read() <func-read>` function.
diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
index 5af0a7179941..f889c20f231c 100644
--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
+++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
@@ -63,6 +63,9 @@ doesn't match the device capabilities. They must instead modify the
interval to match what the hardware can provide. The modified interval
should be as close as possible to the original request.
+Changing the frame interval shall never change the format. Changing the
+format, on the other hand, may change the frame interval.
+
Sub-devices that support the frame interval ioctls should implement them
on a single pad only. Their behaviour when supported on multiple pads of
the same sub-device is not defined.