Hi Richard, On Thu Aug 27 2020, Richard Cochran wrote: > On Tue, Aug 25, 2020 at 11:55:37AM +0200, Kurt Kanzenbach wrote: >> >> I get your point. But how to do it? We would need a timer based on the >> PTP clock in the switch. > > Can't you use an hrtimer based on CLOCK_MONOTONIC? When the switch and the Linux machine aren't synchronized, we would calculate the difference between both systems and could arm the Linux timer based on CLOCK_MONOTONIC. Given the fact that we eight seconds, it would *probably* work when the ptp offset adjustments are in that range. > > I would expect the driver to work based solely on the device's clock. Understood. Thanks, Kurt