[Linuxptp-devel] [RFC PATCH v2 7/9] Implement the COMMON_P2P delay mechanism

[Kishen M. <kis...@in...>]

From: Andrew Zaborowski <and...@in...>

This change implements the COMMON_P2P DM by issuing a request
to the CMLDS for CommonMeanLinkDelayInformation upon expiry of
the delay timer and handles the response to assimilate the
received meanPathDelay and NRR.

Signed-off-by: Andrew Zaborowski <and...@in...>
---
 port.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/port.c b/port.c
index ad13a919f161..946b8235ecd5 100644
--- a/port.c
+++ b/port.c
@@ -1685,6 +1685,10 @@ int port_delay_request(struct port *p)
 {
 	struct ptp_message *msg;
 
+	if (p->delayMechanism == DM_COMMON_P2P) {
+		return port_request_cmlds_info(p);
+	}
+
 	/* Time to send a new request, forget current pdelay resp and fup */
 	if (p->peer_delay_resp) {
 		msg_put(p->peer_delay_resp);
@@ -2597,6 +2601,9 @@ calc:
 				 p->nrate.ratio);
 	}
 
+	p->peer_delay_t1 = t1;
+	p->peer_delay_t2 = t2;
+
 	msg_put(p->peer_delay_req);
 	p->peer_delay_req = NULL;
 }
@@ -3767,7 +3774,33 @@ int process_cmlds_response(struct port *p,
 		 cmlds->scaledNeighborRateRatio, cmlds->egress_ts,
 		 cmlds->rx_ts);
 
-	/* COMMON_P2P DM implementation goes here */
+	if (!cmlds->serviceMeasurementValid) {
+		p->pdr_missing++;
+		port_capable(p);
+		return 0;
+	}
+
+	/* Note: the CMLDS may be using a different local clock.  Do not track
+	 * the CMLDS-clock-to-local-clock rate ratio at this time as the
+	 * difference should be small, or nul with vclocks.
+	 */
+	p->pdr_missing = 0;
+	p->peerMeanPathDelay = cmlds->meanLinkDelay;
+	p->peer_delay = nanoseconds_to_tmv(p->peerMeanPathDelay >> 16);
+	p->nrate.ratio = 1.0 + (double) cmlds->scaledNeighborRateRatio / POW2_41;
+
+	/* Note: this determines the value of port_capable(p), however
+	 * p->peer_portid itself is not actually used outside of the Pdelay FSM.
+	 */
+	p->peer_portid_valid = true;
+	p->nrate.ratio_valid = true;
+
+	if (p->state == PS_UNCALIBRATED || p->state == PS_SLAVE) {
+		clock_peer_delay(p->clock, p->peer_delay,
+				 nanoseconds_to_tmv(cmlds->egress_ts),
+				 nanoseconds_to_tmv(cmlds->rx_ts),
+				 p->nrate.ratio);
+	}
 
 	return 0;
 }
-- 
2.31.1