If head is 0, last will be addressing the index 0 instead of clock->size
-1. Luckily clock->head is unsiged, otherwise it would be addressing
0xffffffff.
Nontheless, this is not the intented behaviour and should be fixed.
Fixes: 66847ef013cc ("[media] uvcvideo: Add UVC timestamps support")
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_video.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d4b023d4de7c..4ff4ab4471fe 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -732,7 +732,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
goto done;
first = &clock->samples[clock->head];
- last = &clock->samples[(clock->head - 1) % clock->size];
+ last = &clock->samples[(clock->head - 1 + clock->size) % clock->size];
/* First step, PTS to SOF conversion. */
delta_stc = buf->pts - (1UL << 31);
--
2.40.0.rc1.284.g88254d51c5-goog-b4-0.11.0-dev-696ae
