From: Kent Gibson <warthog618@gmail.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Jack Winch <sunt.un.morcov@gmail.com>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Linus Walleij <linus.walleij@linaro.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: Suggestion - Configurable Source Clock Type for Line Event Timestamping
Date: Mon, 12 Oct 2020 22:21:52 +0800 [thread overview]
Message-ID: <20201012142152.GA100342@sol> (raw)
In-Reply-To: <CAMRc=MdCWsdRm5eiti6ZHHxZ1UJ3+0+acTdcrE_pq5hmhV7xNg@mail.gmail.com>
On Mon, Oct 12, 2020 at 03:39:21PM +0200, Bartosz Golaszewski wrote:
> On Mon, Oct 12, 2020 at 1:01 PM Jack Winch <sunt.un.morcov@gmail.com> 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?
>
Could we make that GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME, as it
controls the source of the timestamp in struct gpio_v2_line_event?
Otherwise I don't see any problem with it, and I can have a patch out in
a day or two.
Cheers,
Kent.
next prev parent reply other threads:[~2020-10-12 14:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-11 14:15 Suggestion - Configurable Source Clock Type for Line Event Timestamping Jack Winch
2020-10-12 5:06 ` Kent Gibson
2020-10-12 7:23 ` Jack Winch
2020-10-12 9:14 ` Kent Gibson
2020-10-12 10:21 ` Bartosz Golaszewski
2020-10-12 10:05 ` Jack Winch
2020-10-12 13:39 ` Bartosz Golaszewski
2020-10-12 14:21 ` Kent Gibson [this message]
2020-10-12 14:25 ` Bartosz Golaszewski
2020-10-13 8:42 ` Linus Walleij
2020-10-14 11:07 ` Jack Winch
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