[PATCH 1/1] media: Documentation: Improve PIXEL_RATE control documentation

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Document explicitly that the PIXEL_RATE control reflects the actual
frequency at which the pixels are read in the pixel array. It is thus
orthogonal to analogue binning.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 .../userspace-api/media/v4l/ext-ctrls-image-process.rst      | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
index 6d516f041ca2..8616bcd67270 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-process.rst
@@ -41,6 +41,11 @@ Image Process Control IDs
     The configuration of the frame rate is performed by selecting the desired
     horizontal and vertical blanking. The unit of this control is Hz.
 
+    Note that this control isn't affected by analogue binning as the pixels are
+    still being read at the same frequency as without analogue binning, only
+    what is being read is different (a single pixel value vs. a binned pixel
+    value based on the values of two or more pixels).
+
 ``V4L2_CID_TEST_PATTERN (menu)``
     Some capture/display/sensor devices have the capability to generate
     test pattern images. These hardware specific test patterns can be
-- 
2.47.3