| Message ID | 1392497585-5084-5-git-send-email-sakari.ailus@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sakari, Thank you for the patch. On Saturday 15 February 2014 22:53:02 Sakari Ailus wrote: > The UVC device provided timestamps are taken from the clock once the > exposure of the frame has begun, not when the reception of the frame would > have been finished as almost anywhere else. Show this to the user space by > using V4L2_BUF_FLAG_TSTAMP_SRC_SOE buffer flag. > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Strictly speaking that's not entirely true, as some devices don't bother reporting a hardware timestamp. However, in practice, most devices should behave correctly, so that flag is definitely better. Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/media/usb/uvc/uvc_queue.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvc_queue.c > b/drivers/media/usb/uvc/uvc_queue.c index cd962be..a9292d2 100644 > --- a/drivers/media/usb/uvc/uvc_queue.c > +++ b/drivers/media/usb/uvc/uvc_queue.c > @@ -149,7 +149,8 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum > v4l2_buf_type type, queue->queue.buf_struct_size = sizeof(struct > uvc_buffer); > queue->queue.ops = &uvc_queue_qops; > queue->queue.mem_ops = &vb2_vmalloc_memops; > - queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > + queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC > + | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; > ret = vb2_queue_init(&queue->queue); > if (ret) > return ret;
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c index cd962be..a9292d2 100644 --- a/drivers/media/usb/uvc/uvc_queue.c +++ b/drivers/media/usb/uvc/uvc_queue.c @@ -149,7 +149,8 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, queue->queue.buf_struct_size = sizeof(struct uvc_buffer); queue->queue.ops = &uvc_queue_qops; queue->queue.mem_ops = &vb2_vmalloc_memops; - queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; + queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC + | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; ret = vb2_queue_init(&queue->queue); if (ret) return ret;
The UVC device provided timestamps are taken from the clock once the exposure of the frame has begun, not when the reception of the frame would have been finished as almost anywhere else. Show this to the user space by using V4L2_BUF_FLAG_TSTAMP_SRC_SOE buffer flag. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> --- drivers/media/usb/uvc/uvc_queue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)