> -----Original Message----- > From: UWbadgers16 [mailto:uwbadger...@gmail.com] > Sent: Thursday, November 08, 2018 2:59 PM > To: linuxptp-users@lists.sourceforge.net > Subject: [Linuxptp-users] HWTSTAMP_FILTER_ALL > > I'm using v1.8 of Linux PTP on CentOS 3.10.0-693. In addition to using the > ptp4l > service, I also have to hardware timestamp reception of packets coming from > another > device. I use HWTSTAMP_FILTER_ALL to achieve this. When ptp4l initially > starts, it > changes the policy to HWTSTAMP_FILTER_PTP_V2_EVENT. Once ptp4l has finished > its > initial syncing of the clocks, I change the policy back to > HWTSTAMP_FILTER_ALL. >
What hardware are you using (and what driver?)? ptp4l should be using HWTSTAMP_FILTER_ALL if it's supported... What does the output of ethtool -T <device> show for your ethernet device? > This works for awhile, but eventually I tend to see the offset become too > large. It > seems that when I switch back to HWTSTAMP_FILTER_ALL, it causes ptp4l to have > trouble keeping the clocks synced. I make sure to only modify the rx filter > by issuing an > iotcl(SIOCGHWTSTAMP) first, but it still has issues. Can you show us the ptp4l output you're seeing where the clocks drift apart? And this only reproduces if you change to HWTSTAMP_FILTER_ALL? Is the other application doing only receive timestamps? > > My initial impression is that so long as I'm using HWTSTAMP_FILTER_ALL, ptp4l > should have the timestamps that it needs. Will changing this filter setting > after ptp4l > has already started cause issues? I understand that the latest development > branch > has a "hwts_filter" option that takes care of a lot of the work, and it might > fix this > problem, but I'm a bit more locked into using v1.8 as it's already baked into > the > CentOS 3.10.0-693 kernel. It should work properly, but there may be device specific limitations, or possibly changing the timestamp mode could cause some changes to clock settings. In most cases I would think that's simply a driver bug, but it could be due to hardware restrictions/workarounds. It's also possible that simply using HWTSTAMP_FILTER_ALL causes extra delays for the hardware.... Thanks, Jake > > Any help would be greatly appreciated. > > Best regards, > John _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
