On Tue, Feb 23, 2021 at 09:00:32AM +0100, Heiko Thiery wrote: > HI Jakub, > > Am Di., 23. Feb. 2021 um 04:00 Uhr schrieb Jakub Kicinski <k...@kernel.org>: > > Why is the PTP interface registered when it can't be accessed? > > > > Perhaps the driver should unregister the PTP clock when it's brought > > down?
I don't see any reason why a clock should stop ticking just because the interface is down. This is a poor driver design, but sadly it gets copied and even defended. > Good question, but I do not know what happens e.g. with linuxptp when > the device that was opened before will be gone. If a network interface goes down, ptp4l will notice via rtnl and close the interface. Then it re-opens the sockets on rtnl up. However, the file descriptor representing the dynamic posix clock stays opened. Thanks, Richard