Re: [Linuxptp-users] clock_servo ntpshm question

[Maciek M. <ma...@ma...>]

The ntpshm servo will put results in the shm and let the other entity
to control the clock - hence it doesn't lock itself and always returns the
SERVO_UNLOCKED. I'd recommend setting up ptp4l with one of regular
servos and use the phc2sys to transfer the offset to the NTP daemon.

Regards
Maciek

> -----Original Message-----
> From: Marco Davids (SIDN) via Linuxptp-users <linuxptp-
> us...@li...>
> Sent: Friday, July 8, 2022 11:04 PM
> To: lin...@li...
> Subject: [Linuxptp-users] clock_servo ntpshm question
> 
> Hi,
> 
> So, I decided to configure 'clock_servo ntpshm' to use LinuxPTP as a 'refclock'
> for an NTP-daemon on a server with software time stamping.
> 
> And it appeared to worked well, until I looked a bit closer.
> 
> I noticed that with 'ntpshm' the servo state remains 's0' and the port state
> remains UNCALIBRATED.
> 
> By choosing 'linreg' and enable the 'local' refclock in NTP I got it working as
> expected, but I find this a suboptimal solution.
> 
> So, I would like to understand why ptp4l won't move to 's2' / SLAVE status in
> servo_clock ntpshm mode.
> 
> Anyone?
> 
> Thanks!
> 
> --
> Marco