> -----Original Message----- > From: Thomas Behn [mailto:thomas.b...@meinberg.de] > Sent: Tuesday, December 04, 2018 10:04 PM > To: Keller, Jacob E <jacob.e.kel...@intel.com>; > linuxptp-devel@lists.sourceforge.net > Subject: Re: [Linuxptp-devel] PHC delay when calling clock_gettime > > Am 04.12.18 um 19:54 schrieb Keller, Jacob E: > >> -----Original Message----- > >> From: Thomas Behn [mailto:thomas.b...@meinberg.de] > >> Sent: Tuesday, December 04, 2018 12:46 AM > >> To: Keller, Jacob E <jacob.e.kel...@intel.com>; linuxptp- > de...@lists.sourceforge.net > >> Subject: Re: [Linuxptp-devel] PHC delay when calling clock_gettime > > Ah. Ok. From the sound of the original statement it sounded like you were > developing your own hardware. > > > > I suspect that there is a work around in the 82579V NIC that causes this, > > but I don't > know offhand. I'll have to go dig a bit, the e1000e driver isn't one I worked > on much > myself. > > > > Thanks, > > Jake > > Thanks again for your help! > > In case this really is caused by a work around in the 82579V, are there > other NICs, which have similar impairments? > I am asking, because I want to make my implementation as robust as > possible for all kinds of hardware. > > Thanks, > Thomas >
I've never heard of this symptom being reported before. My gut reaction is that this is caused by code in e1000e_read_systim, which reads the SYSTIME multiple times. I am suspicious that multiple readings is somehow impacting the clock time, which would give the results that you see above. You mentioned another board that didn't have this problem using the same driver? Thanks, Jake _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
