Hello Frank, Does the kernel you are running include these <https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1456350.html> fixes to the CPTS (or something equivalent)?
Until the patches above were applied to mainline the CPTS driver would miss TX timestamps once in a while. I can’t be sure this is the cause of your issue but it’s something that will affect your setup sooner or later. I haven’t tried the patches above myself but they should be equivalent to a fix I had to apply to a vendor kernel in the past. HTH — Delio > On 25 Aug 2017, at 10:44, frank <sound...@gmx.net> wrote: > > > > On 08/24/2017 10:24 AM, frank wrote: >> Hi, >> >> On 08/24/2017 10:03 AM, Richard Cochran wrote: >>> On Thu, Aug 24, 2017 at 09:31:26AM +0200, frank wrote: >>>> i have a small number (3-10) of beagle bone blacks observing sensor >>>> events, and measuring the relative timing between these events. >>> >>> And how are these multiple boards connected to each other? >> >> There are two or three 5-port switches which are all connected. I think >> there were two switches used when the pmc command shown was run. >> >> 4 ports are used for the beagles and the 5th port is connected to the >> next switch. > > Hi, > > I have checked the kernel messages of one of the nodes with a large > ptpoffset and found the following log messages: > > Mon May 22 08:03:08 2017 kern.err kernel: [ 428.840562] cpts: unable to > obtain a time stamp > Mon May 22 08:03:14 2017 kern.err kernel: [ 434.887720] cpts: unable to > obtain a time stamp > Mon May 22 08:03:16 2017 kern.err kernel: [ 436.860546] cpts: event > pool is empty > Mon May 22 08:03:16 2017 kern.err kernel: [ 436.864419] cpts: unable to > obtain a time stamp > Mon May 22 08:03:19 2017 kern.err kernel: [ 439.744010] cpts: event > pool is empty > > I have searched the mailing-list and it looks like this was mentioned > before, unfortunately I found no clear outcome. > > kind regards > Frank > > ------------------------------------------------------------------------------ > 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 ------------------------------------------------------------------------------ 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
