The frame leaves the MAC later than the moment its hardware transmit
timestamp is latched, because of the clock domain crossing and the PHY.
This fixed delay is the egressLatency port parameter of IEEE 1588.
Add the configured latency to every hardware transmit timestamp
obtained through MSG_ERRQUEUE, the counterpart of the ingress
compensation.
- Add CONFIG_NETUTILS_PTPD_EGRESS_LATENCY_NS (default 0, which applies
no compensation).
- Add the -O option to override it at run time.
- Add egress_latency_ns to struct ptpd_config_s.
Software timestamps are not affected.
Assisted-by: Claude:claude-sonnet-5
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>