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.
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. 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. 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
