Re: Suggestion - Configurable Source Clock Type for Line Event Timestamping

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Mon, Oct 12, 2020 at 1:01 PM Jack Winch <sunt.un.morcov@xxxxxxxxx> wrote:
>

[snip]

>
> > We still haven't released uAPI v2 so I'm open to some last-minute
> > changes if they make sense (as you explained in the other email about
> > in-kernel timestamping) and are posted soon (before rc3-rc4). I'd like
> > to hear Arnd's opinion on this first though.
>
>
> What's the timescales for this?  As I would be doing this in a
> personal capacity, I will likely have to look at this over a couple of
> weeks.  I would also be limited to testing on an ARMv8 platform, as I
> currently have limited access to hardware.
>

It would be 3-4 weeks from now.

In terms of effort: it doesn't look too complicated. It looks like we
need to add a new flag to the uAPI:
GPIO_V2_LINE_FLAG_EDGE_CLOCK_REALTIME which would make the edge
detector use the real-time clock. I wouldn't stress too much about the
performance of obtaining the timestamp - it's probably negligible
compared to passing the event struct over to user-space.

Kent does the above look right?

Bart

[snip]