Re: [PATCH] media: uvcvideo: Implement V4L2_EVENT_FRAME_SYNC

[Ricardo Ribalda]

Hi Laurent

On Mon, 6 Nov 2023 at 11:42, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Nov 06, 2023 at 12:39:26PM +0200, Laurent Pinchart wrote:
> > On Fri, Oct 20, 2023 at 06:41:45AM +0000, Ricardo Ribalda wrote:
> > > Add support for the frame_sync event, so user-space can become aware
> > > earlier of new frames.
> > >
> > > Suggested-by: Esker Wong <esker@xxxxxxxxxxxx>
> > > Tested-by: Esker Wong <esker@xxxxxxxxxxxx>
> > > Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> > > ---
> > > We have measured a latency of around 30msecs between frame sync
> > > and dqbuf.
> >
> > Not surprising, especially for large resolutions. I'm curious though,
> > what do you use this event for ?

I think Esker is using it to get more accurate power measurements of
the camera stack.

> > It's easy to miss the ++ there when reading the code, would the
> > following be more readable ?

Actually that was my original code, but I thought you would like this better :)

Thanks for the review, a v2 is on its way.

> --
> Regards,
>
> Laurent Pinchart



-- 
Ricardo Ribalda