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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2012-01-15 13:53:45 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-02-27 13:16:22 -0300
commit8e57dec0454d8a3ba987d18b3ab19922c766d4bc (patch)
tree3a1fc754e6bb355b8b0a86100ce661392606a73d /drivers/media
parentfda27874de91d5a8b9a018b3bc74b14578994908 (diff)
[media] [FOR,v3.3] uvcvideo: Avoid division by 0 in timestamp calculation
Use system timestamps if the timestamp can't be computed from the data sent by the device. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/video/uvc/uvc_video.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index c7e69b8f81c..4a44f9a1bae 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -611,9 +611,11 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
delta_stc = buf->pts - (1UL << 31);
x1 = first->dev_stc - delta_stc;
x2 = last->dev_stc - delta_stc;
+ if (x1 == x2)
+ goto done;
+
y1 = (first->dev_sof + 2048) << 16;
y2 = (last->dev_sof + 2048) << 16;
-
if (y2 < y1)
y2 += 2048 << 16;
@@ -631,14 +633,16 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
x1, x2, y1, y2, clock->sof_offset);
/* Second step, SOF to host clock conversion. */
- ts = timespec_sub(last->host_ts, first->host_ts);
x1 = (uvc_video_clock_host_sof(first) + 2048) << 16;
x2 = (uvc_video_clock_host_sof(last) + 2048) << 16;
- y1 = NSEC_PER_SEC;
- y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
-
if (x2 < x1)
x2 += 2048 << 16;
+ if (x1 == x2)
+ goto done;
+
+ ts = timespec_sub(last->host_ts, first->host_ts);
+ y1 = NSEC_PER_SEC;
+ y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
/* Interpolated and host SOF timestamps can wrap around at slightly
* different times. Handle this by adding or removing 2048 to or from