v4l2: Document expected fallthrough

Compilers may now enable warnings for implicit fallthrough of switch
case statements, to help catch errors. One such case is highlighted in
our v4l2 module:

v4l2.c: In function ‘v4l2_enum_frame_sizes’:
v4l2.c:179:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
    frame->step_height = frmenum.stepwise.step_height;
    ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
v4l2.c:180:3: note: here
   case V4L2_FRMSIZE_TYPE_CONTINUOUS:
   ^~~~

This fall through is expected, and the warning can be removed simply by
adding a comment to confirm that.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/v4l2.c b/v4l2.c
index a0036fd..f97a054 100644
--- a/v4l2.c
+++ b/v4l2.c
@@ -177,6 +177,7 @@ v4l2_enum_frame_sizes(struct v4l2_device *dev, struct v4l2_format_desc *format)
 		case V4L2_FRMSIZE_TYPE_STEPWISE:
 			frame->step_width = frmenum.stepwise.step_width;
 			frame->step_height = frmenum.stepwise.step_height;
+			/* fallthrough */
 		case V4L2_FRMSIZE_TYPE_CONTINUOUS:
 			frame->min_width = frmenum.stepwise.min_width;
 			frame->min_height = frmenum.stepwise.min_height;