Re: [PATCH] media: uvcvideo: Fix annotation for uvc_video_clock_update()
From: Laurent Pinchart
Date: Wed Jan 01 2020 - 12:28:46 EST
Hello Jun,
Thank you for the patch.
On Wed, Dec 25, 2019 at 10:34:17AM +0800, Jun Chen wrote:
> From: Jun Chen <jun.chen@xxxxxxxxxx>
>
> The formula (2) is to convert from SOF to host clock,
> it should be fix as
> "TS = ((TS2 - TS1) * SOF + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1)"
>
> Signed-off-by: Jun Chen <jun.chen@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
and applied to my tree.
> ---
> 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 8fa77a8..a3150da 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -622,7 +622,7 @@ static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample)
> * to avoid losing precision in the division. Similarly, the host timestamp is
> * computed with
> *
> - * TS = ((TS2 - TS1) * PTS + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2)
> + * TS = ((TS2 - TS1) * SOF + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2)
> *
> * SOF values are coded on 11 bits by USB. We extend their precision with 16
> * decimal bits, leading to a 11.16 coding.
--
Regards,
Laurent Pinchart