Hi.
In Linux kernel HWTSTAMP_TX_ONESTEP_P2P is introduced as feature
superset of HWTSTAMP_TX_ONESTEP_SYNC for peer delay. However only few
device drivers and its hardware support full P2P one-step timestamping.
It is not clear if one-step SYNC and two-step Pdelay method in P2P can
be mixed together (by single OC/BC master) when HWTSTAMP_TX_ONESTEP_SYNC
is supported only:
- According to IEEE1588-2008 specification (11.4.3) peer delay responder
one-step clock "SHALL" (key word) update Pdelay_resp on the fly so it
seems they can't be mixed.
- Moreover "one-step clock" term suggests it is clock property, not port
timestamping ability. On the other hand it seems artifical requirement.
1. Can you clarify for one-step P2P what is met in the field (eg. PTP
Plugfest) ?
2. And what is formal IEEE1588 requirement/statement ?
3. Is such P2P mix supported/handled properly by TC and OC/BC slaves? It
looks supported (both OC slave and master) by linuxptp 4.0 and 3.1
(port.c::process_pdelay_req()).
4. The latest gPTP and power profile have recommendation for one-step.
Do they allow/mean one-step SYNC only or full P2P with Pdelay ?
best regards
Janusz
_______________________________________________
Linuxptp-users mailing list
Linuxptp-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linuxptp-users
