[media] DocBook: mention that EINVAL can be returned for invalid menu indices

The documentation suggested that if the control value is wrong only
ERANGE can be returned. But in some cases (an invalid menu index)
EINVAL can also be returned. Clarify this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml b/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml
index 12b1d0503e2..ee2820d6ca6 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-ctrl.xml
@@ -64,7 +64,9 @@ return an &EINVAL;. When the <structfield>value</structfield> is out
 of bounds drivers can choose to take the closest valid value or return
 an &ERANGE;, whatever seems more appropriate. However,
 <constant>VIDIOC_S_CTRL</constant> is a write-only ioctl, it does not
-return the actual new value.</para>
+return the actual new value. If the <structfield>value</structfield>
+is inappropriate for the control (e.g. if it refers to an unsupported
+menu index of a menu control), then &EINVAL; is returned as well.</para>
 
     <para>These ioctls work only with user controls. For other
 control classes the &VIDIOC-G-EXT-CTRLS;, &VIDIOC-S-EXT-CTRLS; or
@@ -99,7 +101,9 @@ application.</entry>
 	<term><errorcode>EINVAL</errorcode></term>
 	<listitem>
 	  <para>The &v4l2-control; <structfield>id</structfield> is
-invalid.</para>
+invalid or the <structfield>value</structfield> is inappropriate for
+the given control (i.e. if a menu item is selected that is not supported
+by the driver according to &VIDIOC-QUERYMENU;).</para>
 	</listitem>
       </varlistentry>
       <varlistentry>