Thanks for the response. Between what you wrote and some more spelunking, I
think I finally understand. I'll summarize it here in case it's useful to
others.
1. The PPS from the GPS that you feed into the PHC has nothing to do with
the kernel PPS system. It is simply an input on one of the pins of
On Mon, May 20, 2019 at 07:18:22AM -0400, Sanjay Bhandari wrote:
> Thanks for the response. Between what you wrote and some more spelunking, I
> think I finally understand. I'll summarize it here in case it's useful to
> others.
That is a good summary.
> 1. The PPS from the GPS that you feed int
> Note that phc2sys can (and usually does) work without that kernel PPS
event. In fact, depending on ISR latency, the synchronization probably
works better without the PPS.
That's interesting. Thanks for pointing this out. It goes counter to my
intuition (but it makes sense).
I see in the phc2sy
On Mon, May 20, 2019 at 10:29:49AM -0400, Sanjay Bhandari wrote:
> I see in the phc2sys code that when not using PPS, it uses ioctls to get
> time offsets (PTP_SYS_OFFSET_PRECISE etc.). I suppose you are saying that
> this a more accurate mechanism than the one based on PPS. How close can you
> get
On Mon, May 20, 2019 at 05:10:26PM +0200, Miroslav Lichvar wrote:
> error, except the nanosecond resolution. The NICs supported by the
> e1000e driver using ART for cross timestamping seem to be better than
> 1 microsecond and are possibly much better than that, but there
> doesn't seem to be any d
Not sure if these actually have anything to do with each other - but with
my limited insight, it seems like they do. Some help please.
In the man page it says:
> With the *-a* option, the clocks to synchronize are fetched from the
running *ptp4l* daemon and the direction of synchronization automa
> -Original Message-
> From: Richard Cochran [mailto:richardcoch...@gmail.com]
> Sent: Monday, May 20, 2019 9:11 AM
> To: Miroslav Lichvar
> Cc: Sanjay Bhandari ;
> linuxptp-users@lists.sourceforge.net;
> Keller, Jacob E
> Subject: Re: [Linuxptp-users] Is the PPS timestamp system time or
On Mon, May 20, 2019 at 12:31:07PM -0400, Sanjay Bhandari wrote:
> > With the *-a* option, the clocks to synchronize are fetched from the
> running *ptp4l* daemon and the direction of synchronization automatically
> follows changes of the PTP port states.
>
> Is this talking about multiple PTP por
