[media] V4L2 Spec: improve the G/S_INPUT/OUTPUT documentation
As Rupert pointed out, the phrase "It is good practice" should be replaced
with "You must".
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Rupert Eibauer <Rupert.Eibauer@ces.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-input.xml b/Documentation/DocBook/media/v4l/vidioc-g-input.xml
index 08ae82f..1d43065 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-input.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-input.xml
@@ -61,8 +61,8 @@
<constant>VIDIOC_S_INPUT</constant> ioctl with a pointer to this
integer. Side effects are possible. For example inputs may support
different video standards, so the driver may implicitly switch the
-current standard. It is good practice to select an input before
-querying or negotiating any other parameters.</para>
+current standard. Because of these possible side effects applications
+must select an input before querying or negotiating any other parameters.</para>
<para>Information about video inputs is available using the
&VIDIOC-ENUMINPUT; ioctl.</para>
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-output.xml b/Documentation/DocBook/media/v4l/vidioc-g-output.xml
index fd45f1c..4533068 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-output.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-output.xml
@@ -61,8 +61,9 @@
<constant>VIDIOC_S_OUTPUT</constant> ioctl with a pointer to this integer.
Side effects are possible. For example outputs may support different
video standards, so the driver may implicitly switch the current
-standard. It is good practice to select an output before querying or
-negotiating any other parameters.</para>
+standard.
+standard. Because of these possible side effects applications
+must select an output before querying or negotiating any other parameters.</para>
<para>Information about video outputs is available using the
&VIDIOC-ENUMOUTPUT; ioctl.</para>