- ptp_clock.c replaces the 3.1 logger: UDP/IPv4 multicast, E2E.
Announce: IEEE 1588 dataset comparison picks the best GM, dropped after
announceReceiptTimeout x its announce interval. Sync/Follow_Up (two-step
and one-step) with HW t2 and correctionField. Delay_Req sent as a raw
frame (DSCP ptp.dscp, TTL 1, clockIdentity = EUI-64 from MAC) with HW
TX timestamp t3, randomised at the GM's Delay_Resp interval; Delay_Resp
matched on requestingPortIdentity + seq.
- Path delay corrected for offset drift between t2 and t3 (rate from
consecutive Syncs) so it is right before the clock is syntonised.
- ptp_hw: ptp_hw_send_event() builds Eth/IPv4/UDP 319 and returns the HW
TX timestamp.
- Verified vs ptp4l (i210 GM, HP 2530 non-PTP switch, PC 1G / board 100M):
GM selected, path delay settles at ~10.3 us and stays flat, rate
-39.8 +-0.4 ppm, offset drifts at -40 us/s (no servo yet).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
