On Tue, Apr 24, 2018 at 05:10:48PM +0000, Keller, Jacob E wrote: > > -----Original Message----- > > From: Miroslav Lichvar [mailto:mlich...@redhat.com] > > Sent: Tuesday, April 24, 2018 12:16 AM > > To: Cliff Spradlin <thr...@google.com> > > Cc: linuxptp-users@lists.sourceforge.net > > Subject: Re: [Linuxptp-users] ptp4l and SyncE > > > > I have a pair of directly connected X550 cards, which behave a bit > > like SyncE with the frequency. Their clocks seem to be locked to each > > other or some other common source. I'm not sure how this works and I'd > > love to see some explanation. > > If it's two different X550 cards, I don't know. If it's two ports of the same > card, the devices *do* share the same clock source (but you can't atomically > set the registers for them, so it's not feasible to set it up as a proper > boundary clock)
It's two different X550T cards. They have one port connected to the same switch and one port connected directly between them. Maybe the cards use one clock for both MAC and PHY layers? If the two ports of one card shared the clock too, that wouldn't work with different ports running at slightly different frequencies, right? (I don't know much about Ethernet and whether any of this makes any sense). -- 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-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
