On Wed, Apr 01, 2020 at 11:06:29AM +0000, Patrick Nowak wrote: > My conclusion is, that I am either reading the log messages completly wrong > or my setup is broken. Is my assumption correct, that the offset from both > ptp4l and phc2sys should give me a good idea about how far off both system > clocks are? If not, how can I truly measure the offset between the two system > clocks and further investigate the problems I am seeing?
Offsets don't tell you anything about accuracy, only stability. An upper bound on the error is half of the roundtrip delay between the two system clocks. That includes the PCIe delay, delays in HW timestamping and the network delay. Of course, if you had some magic hardware that allowed you to measure the error directly, you could compensate for it in ptp4l/phc2sys configuration. -- Miroslav Lichvar _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
