> 21.07.2022 13:06 Miroslav Lichvar <mlich...@redhat.com> wrote: > > > On Thu, Jul 21, 2022 at 12:41:54PM +0200, Jakub Raczyński wrote: > > > 21.07.2022 10:20 Miroslav Lichvar <mlich...@redhat.com> wrote: > > > No, that's not correct. Try running the ntpshmmon tool from gpsd to > > > see that phc2sys is writing new samples in both directions. > > > > You are mistaken, I did try ntpshmmon and it does write to ntpshm only in > > one direction as Slave. > > Well, that means there is something wrong with your setup. > > > As such, since data is not written to ntpshm, I assume that phc2sys does > > select direction incorrectly after ntpd reset when significant offset was > > present. Seems like servo reset issue that does not update direction or > > sets it incorrectly. I will probably debug it in following days but I had > > hoped you could be of assistance. > > Your interpretation is wrong. > > If you looked at the code, you would see that the ntpshm servo is only > writing to the segment. It doesn't know if there is anything reading > that data, or what happens with it. ntpd cannot communicate with > phc2sys over the SHM.
I fail to understand that, what could be wrong? I have one-to-one device connection where i only change priority1 of devices to select which should be Slave or Master. My interpretation is based only on ntpshmmon tool - it clearly shows that ntpshm servo is only fed when PTP portState is set to Slave. So it is used only to write to the segment, but phc2sys clearly controls when it is done. Since ntpd does not communicate with phc2sys then whether it works or not is only based on phc2sys. It seems you have great feature of phc2sys that allows to synchronize ntpshm servo in Slave state and use CLOCK_REALTIME as Master, yet you say like it does not exist. And again, I intend to use it that way. I am not trying to read anything from ntpshm. Anyway, as said, I will look into it soon. Best regards Jakub Raczynski _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
