Re: [Linuxptp-users] phc offset explodes after a while

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

On Thu, Jan 30, 2014 at 04:22:22PM +0000, Ledda William EXT wrote:
> Are you able to find the same jump of origin in the tcpdump (look for the Follow_up messages)? 
> 
> If yes the problem is in your master clock device.

Yes, in the PCAP file there is a jump in the follow up messages.

Packet 28 has seconds = 1391093891.
Packet 36 has seconds = 1391164261.

The difference is 70370 seconds. That seems to be consistent with your
other logs.

Your PCA (64 bit kernel) is the slave, and your PCB (32 bit kernel) is
the master. The source of the problem is in the master.

Here are a few questions to answer to get to the bottom of this:

1. Maybe there is another program on host PCB that is resetting the
   time of the PTP clock?

2. What happens when you run with the roles reversed?
   Use ptp4l -s on host PCB.

3. On host PCB, try the following script with nothing else running.

	testptp -s
	while [ 1 ]; do
		date;
		testptp -g;
		sleep 1;
	done

   Does the sudden jump in time also occur?  The testptp program is
   under /Documentation/ptp in the Linux kernel sources.

Thanks,
Richard