[Linuxptp-users] Synchronization problem

[Ledda W. E. <Wil...@it...>]

Hi all, 
I have encountered a strange behaviour using ptp4l. I have a system with Linux RH 6.4 and I'm using the package included in the Red Hat 6.4 distribution (linuxptp-0-0.6.20121114gite6bbbb.el6.x86_64). To synch the system time I use a motherboard with a Broadcom chipset that support only SW timestamp. It's ok, and I'm able to synch the system clock with our GMC with ptp4l. 

Today I was trying to make a trivial but very important test for our purposes: with the system clock already synch with the GMC I have tried to change the date of the system to discover how much time ptp4l takes to reset the system clock to the right time. The result is not good, since the time is never re-synchronized. If I stop the ptp4l and I restart it the system is synchronized again.

I attach two files:

- Ptp4l-sync: system time bad -> system time synchronize
- Ptp4l-not-synch: system synch -> system time force to be bad. After about five minutes the system is not syched.

Regards

William