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Commit 8e57dec0 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab
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[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: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent fda27874

drivers/media/video/uvc/uvc_video.c

+9 −5
Original line number Diff line number Diff line
@@ -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