On Tue, Aug 01, 2017 at 07:37:44AM +0000, Rommel, Albrecht wrote: > This is a general question to the handling of ptp4l and phc2sys (-a -r) > running on PTP nodes: > > Assuming PTP aware nodes (i.e. a 1588 capable switch acting as a BC, or an > end application acting as a PTP slave) are running ptp4l and probably phc2sys > (-a -r) for CLOCK_REALTIME synchronization. > These nodes assume a monotonously increasing PTP time. If (i.e. due to > re-arrangements within the time master) the PTP time becomes non-monotonous > (in worst case: jumping backwards in time), subsequent downstream nodes get > confused. According to our observation, ptp4l and phc2sys on the downstream > nodes require a restart for proper operation. How is this signaling handled > in practice?
If you expect large offsets to occur in normal operation, you can configure the step threshold for both ptp4l and phc2sys. Restarting shouldn't be necessary. By default, they allow step only on the first update. After that, a large offset is corrected slowly by slewing. -- Miroslav Lichvar ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
