[media] DocBook: various updates w.r.t. v4l2_buffer and multiplanar
Clarify the behavior of v4l2_buffer in the multiplanar case,
including fixing a false statement: you can't set m.planes to NULL
when calling DQBUF.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index 97f785a..b5d1cbd 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -677,8 +677,10 @@
<entry><structfield>length</structfield></entry>
<entry></entry>
<entry>Size of the buffer (not the payload) in bytes for the
- single-planar API. For the multi-planar API should contain the
- number of elements in the <structfield>planes</structfield> array.
+ single-planar API. For the multi-planar API the application sets
+ this to the number of elements in the <structfield>planes</structfield>
+ array. The driver will fill in the actual number of valid elements in
+ that array.
</entry>
</row>
<row>