Re: [Linuxptp-users] Installation of Linuxptp on Ubuntu PC

[Guo H. <gh...@gm...>]

Hi Richard,

Finally, I can make the ptp4l program works and the output of ptp4l -E -2
-H -i eth0 -m -q is shown as below:

ptp4l[7709.666]: master offset        -46 s2 freq   +3798 path delay
828
ptp4l[7710.667]: master offset         68 s2 freq   +3898 path delay
828
ptp4l[7711.669]: master offset         40 s2 freq   +3890 path delay
831
ptp4l[7712.672]: master offset         41 s2 freq   +3903 path delay
831
ptp4l[7713.678]: master offset         43 s2 freq   +3918 path delay
831
ptp4l[7714.679]: master offset        -77 s2 freq   +3810 path delay
831
ptp4l[7715.679]: master offset         41 s2 freq   +3905 path delay
831
ptp4l[7716.685]: master offset         39 s2 freq   +3916 path delay
830
ptp4l[7717.689]: master offset        -52 s2 freq   +3836 path delay
830
ptp4l[7718.692]: master offset        -34 s2 freq   +3839 path delay
829
ptp4l[7719.695]: master offset        -28 s2 freq   +3835 path delay
828
ptp4l[7720.697]: master offset        -50 s2 freq   +3804 path delay
828
ptp4l[7721.701]: master offset         95 s2 freq   +3934 path delay
828
ptp4l[7722.702]: master offset        -27 s2 freq   +3841 path delay
828
ptp4l[7723.703]: master offset         -3 s2 freq   +3857 path delay
828
ptp4l[7724.705]: master offset        -33 s2 freq   +3826 path delay
828
ptp4l[7725.709]: master offset        -20 s2 freq   +3829 path delay
827
ptp4l[7726.711]: master offset         -8 s2 freq   +3835 path delay
825

Does this mean the clock offset between the 82574 NIC and the Master Clock
is in the range less than 100 ns?

After that I make install the linuxptp package and follow the instruction
from Red Hat:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/s1-Using_the_PTP_management_Client.html

I can use the pmc and phc2sys utilities and the output of phc2sys -s eth0
-w -m -q is shown below:

phc2sys[7981.691]: phc offset       -70 s2 freq  -22120 delay  13340
phc2sys[7982.691]: phc offset       -81 s2 freq  -22152 delay  13270
phc2sys[7983.691]: phc offset       -46 s2 freq  -22141 delay  13340
phc2sys[7984.691]: phc offset        70 s2 freq  -22039 delay  13340
phc2sys[7985.692]: phc offset        48 s2 freq  -22040 delay  13410
phc2sys[7986.692]: phc offset        19 s2 freq  -22055 delay  13340
phc2sys[7987.692]: phc offset       -23 s2 freq  -22091 delay  13410
phc2sys[7988.692]: phc offset       -47 s2 freq  -22122 delay  13340
phc2sys[7989.692]: phc offset        11 s2 freq  -22078 delay  14318
phc2sys[7990.692]: phc offset       -14 s2 freq  -22100 delay  13340
phc2sys[7991.693]: phc offset        27 s2 freq  -22063 delay  13340
phc2sys[7992.693]: phc offset       237 s2 freq  -21845 delay  13829
phc2sys[7993.693]: phc offset      -220 s2 freq  -22231 delay  13340
phc2sys[7994.693]: phc offset       -71 s2 freq  -22148 delay  13340
phc2sys[7995.693]: phc offset      -188 s2 freq  -22286 delay  16483
phc2sys[7996.693]: phc offset       188 s2 freq  -21966 delay  13340
phc2sys[7997.694]: phc offset       119 s2 freq  -21979 delay  13340
phc2sys[7998.694]: phc offset        14 s2 freq  -22048 delay  13340
phc2sys[7999.694]: phc offset       -87 s2 freq  -22145 delay  13270


Does that mean the system time is synchronized to the ptp hardware clock on
the 82574 NIC?


However I cannot run ptp4l and phc2sys as a daemon process under Ubuntu:

root@Hao-Ubuntu:~# service ptp4l start
ptp4l: unrecognized service
root@Hao-Ubuntu:~#

Any idea on this?

I am carrying out a test on verify the timestamp accuracy of an Ethernet
capture card.
This card obtains the ToD info from the host PC while accept the 1-PPS
signal to tick afterwards.

The host PC is synchronized to the GPS clock via Linuxptp (PTP port 1 on
GPS clock in use) and the Ethernet capture card gets the 1-PPS from the
same GPS clock.

Then I connect PTP port 2 of the GPS clock directly to the Ethernet capture
card via 3 m RJ45 cable.
When I compare the timestamp within the Follow_Up and the receipt timestamp
of corresponding Sync by Ethernet capture card, the time difference is
about 1.15 us, which might be not reasonable.

I got similar result around 1.5 us before I used Linuxptp and I used NTP to
sync the host pc with the GPS clock at that moment.

Therefore, I doubt whether there is a inherent delay between the point when
the Ethernet capture card request for the ToD and point the Ethernet
capture card really gets the information or the system time is not
synchronized by the hardware clock of the 82574 NIC.


Thank you very much and look forward to your feedback soon.


Best regards,
    Hao




On 29 August 2015 at 13:59, Richard Cochran <ric...@gm...>
wrote:

> On Sat, Aug 29, 2015 at 12:19:25PM +0100, Guo Hao wrote:
> > Hi Richard,
> >
> > i have 2 Intel 82547 NICs and they should support hardware timestamping.
>                  ^^^^^
> 82574 ?
>
> > Please see below the output of ethtool -T ethx:
>
> Ok, then:
>
> - Download and untar the linuxptp sources.
> - Change into the directory.
> - Type "make"
>
> Then, run the program:
>
>   ./ptp4l -m -q -i eth0
>
>
> HTH,
> Richard
>
>