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, 5 insertions, 0 deletions

diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 1637cc302697..de785da4564c 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -107,6 +107,11 @@ int v4l2_ctrl_query_menu(struct v4l2_querymenu *qmenu,
                 struct v4l2_queryctrl *qctrl, const char **menu_items);
 #define V4L2_CTRL_MENU_IDS_END (0xffffffff)
 int v4l2_ctrl_query_menu_valid_items(struct v4l2_querymenu *qmenu, const u32 *ids);
+
+/* Note: ctrl_classes points to an array of u32 pointers. Each u32 array is a
+   0-terminated array of control IDs. Each array must be sorted low to high
+   and belong to the same control class. The array of u32 pointers must also
+   be sorted, from low class IDs to high class IDs. */
 u32 v4l2_ctrl_next(const u32 * const *ctrl_classes, u32 id);
 
 /* ------------------------------------------------------------------------- */