Re: [Linuxptp-users] strange behavior with free_running regarding offset display

[Tino K. <tin...@al...>]

On Wed, 2015-01-07 at 16:30 +0100, Richard Cochran wrote:
> Tino,
> 
> On Wed, Jan 07, 2015 at 03:10:21PM +0100, Tino Keitel wrote:
> > ptp4l[3620464.599]: rms 34999387468 max 34999407058 freq -19592 +/-   0
> > ptp4l[3620468.598]: rms 34999465846 max 34999485433 freq -19595 +/-   7
> 
> Max here is always positive. It is the absolute value (magnitude) of
> the maximum offset during the interval.
>  
> > Querying ptp4l using pmc gives this output (note the first
> > offsetFromMaster value):
> > 
> > $ pmc -u "get CURRENT_DATA_SET"
> > sending: GET CURRENT_DATA_SET
> > 	001b21.fffe.929906-0 seq 0 RESPONSE MANAGMENT CURRENT_DATA_SET 
> > 		stepsRemoved     2
> > 		offsetFromMaster -35000968295.0
> 
> Here the plain offset is given.
> 
> Both values show the offset error to be about 35 seconds, which is the
> TAI/UTC offset. Probably your PHC driver sets its time to the UTC
> system time when loading.

Hi Richard,

this sounds like it is normal behavior to show the offset to the PHC
even if the PHC is not touched (free_running set to 1).

Regards,
Tino