Hi Richard, > -----Original Message----- > From: Richard Cochran <richardcoch...@gmail.com> > Sent: Tuesday, September 24, 2019 2:28 AM > To: Y.b. Lu <yangbo...@nxp.com> > Cc: Андрей Иванов <ia...@yandex.com>; rodney.greenstr...@gmail.com; > erik.h...@ni.com; linuxptp-devel@lists.sourceforge.net > Subject: Re: [Linuxptp-devel] [Linuxptp-users] How do I implement Sync > message receive timeout according to Automotive and 802.1 AS profiles? > > On Mon, Sep 23, 2019 at 04:17:02AM +0000, Y.b. Lu wrote: > > May I have your suggestion here? To maintain gPTP time in software, I > > just copied kernel timecounter code into linuxptp for usage. > > Why? That sounds wrong.
[Y.b. Lu] May I know TAB based on linuxptp plans to adjust physical clock, or to maintain gPTP time in software. Regarding to physical clock adjustment, that's confusing. This will changes neighbor rate ratio frequently, so the cumulative rate ratio and corrected residence time/path delay in follow_up and TLV will be not correct for the receiver. Regarding to maintaining gPTP time in software, I think this was described in "10.2.12 ClockSlaveSync state machine" of 802.1AS-2011. I currently copied kernel timecounter for this. Is there any better solution? 10.2.12.2.1 updateSlaveTime(): updates the global variable clockSlaveTime (see 10.2.3.3), based on information received from the SiteSync and LocalClock entities. It is the responsibility of the application to filter slave times appropriately (see B.3 and B.4 for examples). As one example, clockSlaveTime can be incremented by localClockTickInterval (see 10.2.3.18) divided by rateRatio member of the received PortSyncSync structure. If no time-aware system is grandmaster-capable, i.e., gmPresent is FALSE, then clockSlaveTime is set to the time provided by the LocalClock. This function is invoked when rcvdLocalClockTick is TRUE. Thanks a lot. Yangbo Lu > > Thanks, > Richard > _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
