[media] DocBook/media/v4l: il_* fields always 0 for progressive formats

Clarify that the il_vfrontporch, il_vsync and il_vbackporch fields must
always be 0 for progressive formats.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml b/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml
index 72369707bd77..c4336577ff06 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml
@@ -156,19 +156,19 @@ bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_H
             <entry>__u32</entry>
             <entry><structfield>il_vfrontporch</structfield></entry>
             <entry>Vertical front porch in lines for the even field (aka field 2) of
-            interlaced field formats.</entry>
+            interlaced field formats. Must be 0 for progressive formats.</entry>
           </row>
           <row>
             <entry>__u32</entry>
             <entry><structfield>il_vsync</structfield></entry>
             <entry>Vertical sync length in lines for the even field (aka field 2) of
-            interlaced field formats.</entry>
+            interlaced field formats. Must be 0 for progressive formats.</entry>
           </row>
           <row>
             <entry>__u32</entry>
             <entry><structfield>il_vbackporch</structfield></entry>
             <entry>Vertical back porch in lines for the even field (aka field 2) of
-            interlaced field formats.</entry>
+            interlaced field formats. Must be 0 for progressive formats.</entry>
           </row>
           <row>
             <entry>__u32</entry>