Re: [Linuxptp-users] About ptp4l sync completed time

[Richard C. <ric...@gm...>]

On Fri, Mar 09, 2012 at 11:30:15AM +0900, Takahiro Shimizu wrote:
> Hello,
> 
> I ran ptp4l around 12 hours.
> The hardware is Intel EG20T.
> The performance is fine.
> The master offset is around 30 (msec) at the beginning.
> And the master offset keeps in +- 1 (usec) after sync is completed.
> However it needs long time till the sync is completed.
> I needed 1 hour about it.
> 
> Question:
> 1. Is this the normal behaviour? Does it need so long time on other
> platforms?

No, it is not normal.

With hardware time stamping, you should get withn 0.1 usec in about
one or two minutes.

> 2. Can I speed up the time till sync completed?

The clock servo (in pi.c) has a PI controller, and its constants do
affect the convergence performance.

However, I think you have errors in the time stamps, or missing time
stamps.

HTH,
Richard