Re: [net-next, v5, 08/11] net: sock: extend SO_TIMESTAMPING for PHC binding

[Richard Cochran]

On Mon, Jul 05, 2021 at 08:19:30AM +0000, Y.b. Lu wrote:
> When several ptp virtual clocks are created, the ptp physical clock is guaranteed for free running.
> 
> What I think is, for timestamping, if no flag SOF_TIMESTAMPING_BIND_PHC, the timestamping keeps using ptp physical clock.
> If application wants to bind one ptp virtual clock for timestamping, the flag SOF_TIMESTAMPING_BIND_PHC should be set and clock index should be provided.
> After all, several ptp virtual clocks created are likely for different timescale/use case. There should be a method for any of applications to select the right one to use.
> 
> Does it make sense?

Yes, indeed.  I totally forgot that the user space PTP stack has
network sockets bond to interfaces, and they are completely separate
from the PHC clockid_t.  Need more sleep...

Thanks,
Richard