V4L/DVB (10544): v4l2-common: add comments warning that about the sort order

Control arrays as are used with v4l2_ctrl_next must be sorted from
low to high. Add a comment at the top of all such arrays to warn
about this.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/media/video/saa7134/saa7134-empress.c b/drivers/media/video/saa7134/saa7134-empress.c
index d9d9607044a7..2e15bb7c3f0a 100644
--- a/drivers/media/video/saa7134/saa7134-empress.c
+++ b/drivers/media/video/saa7134/saa7134-empress.c
@@ -352,6 +352,7 @@ static int empress_s_ctrl(struct file *file, void *priv,
 static int empress_queryctrl(struct file *file, void *priv,
                                         struct v4l2_queryctrl *c)
 {
+        /* Must be sorted from low to high control ID! */
         static const u32 user_ctrls[] = {
                 V4L2_CID_USER_CLASS,
                 V4L2_CID_BRIGHTNESS,
@@ -364,6 +365,7 @@ static int empress_queryctrl(struct file *file, void *priv,
                 0
         };
 
+        /* Must be sorted from low to high control ID! */
         static const u32 mpeg_ctrls[] = {
                 V4L2_CID_MPEG_CLASS,
                 V4L2_CID_MPEG_STREAM_TYPE,