Sorry for getting back late to you. It did not compute when I read your email the first time around, then I let it sit for a while. On Thu, Nov 05, 2020 at 09:18:04PM +0100, Christian Eggers wrote: > unfortunately I made a mistake when testing. Actually the timestamp *must* be > moved from the correction field (negative) to the egress tail tag. That doesn't sound very good at all. I have a simple question. Can your driver, when operating as a PTP master clock, distribute a time in 2020 into your network? (you can check with "phc_ctl /dev/ptp0 get")