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

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

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.

HTH,
Richard