Re: [PATCH net-next] ptp: add vclock timestamp conversion IOCTL

On Mon, 2021-09-27 at 13:23 -0700, Richard Cochran wrote:

What you really want is the socket to return more than one time stamp.
So why not do that instead?

Right now, the SO_TIMESTAMPING has an array of

   struct timespec ts[3] = 
   [0] SOFTWARE
   [1] LEGACY (unused)
   [2] HARDWARE

You can extend that to have

   [0] SOFTWARE
   [1] LEGACY (unused)
   [2] HARDWARE (vclock 0)
   [3] HARDWARE (vclock 1)
   [4] HARDWARE (vclock 2)
   ...
   [N] HARDWARE (vclock N-2)

You could store the selected vclocks in a bit mask associated with the socket.

Hm?

Yes that would do it. Only drawback is that ALL rx and tx timestamps
are converted to the N domains instead of a few as needed.

Before going in this direction, is this a change that you really see as
worthwile for virtual clocks and timetamping support ?

What approach do you have in mind for multi-domain support with the
common CMLDS layer ?

Thanks,
Seb