Re: [Linuxptp-users] Synchronisation troubles

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

On Thu, Jan 24, 2019 at 07:56:10AM -0800, Richard Cochran wrote:
> On Thu, Jan 24, 2019 at 12:53:37PM +0000, Jord Pool wrote:
> > 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-LM
> 
> Assuming the fault comes when running on this port: there are HW
> issues with the i219, IIRC.

You could try this patch:

commit e1f65b0d70e9e5c80e15105cd96fa00174d7c436
Author: Miroslav Lichvar <mli...@re...>
Date:   Tue Oct 23 14:37:39 2018 +0200

    e1000e: allow non-monotonic SYSTIM readings
    
    It seems with some NICs supported by the e1000e driver a SYSTIM reading
    may occasionally be few microseconds before the previous reading and if
    enabled also pass e1000e_sanitize_systim() without reaching the maximum
    number of rereads, even if the function is modified to check three
    consecutive readings (i.e. it doesn't look like a double read error).
    This causes an underflow in the timecounter and the PHC time jumps hours
    ahead.
    
    This was observed on 82574, I217 and I219. The fastest way to reproduce
    it is to run a program that continuously calls the PTP_SYS_OFFSET ioctl
    on the PHC.
    
    Modify e1000e_phc_gettime() to use timecounter_cyc2time() instead of
    timecounter_read() in order to allow non-monotonic SYSTIM readings and
    prevent the PHC from jumping.


Thanks,
Richard