From 450b1ed844f6f5e0e2a0881b08a0afd1d6a2d76a Mon Sep 17 00:00:00 2001
From: Vedang Patel <vedang.patel@intel.com>
Date: Thu, 28 Mar 2019 20:32:31 -0700
Subject: [PATCH] port: Add inhibit_delay_req.

Add provision to disable delay requests. Designated masters who do not
need to calculate pdelay can use this option. This is required by
Automotive Profile to reduce network load.

Signed-off-by: Vedang Patel <vedang.patel@intel.com>
---
 config.c                      |  3 ++-
 configs/automotive-master.cfg |  1 +
 configs/default.cfg           |  1 +
 port.c                        | 10 ++++++++++
 port_private.h                |  1 +
 ptp4l.8                       |  5 +++++
 6 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 0da7ce4..93ea5da 100644
--- a/config.c
+++ b/config.c
@@ -244,8 +244,9 @@ struct config_item config_tab[] = {
 	PORT_ITEM_INT("ignore_transport_specific", 0, 0, 1),
 	PORT_ITEM_INT("ingressLatency", 0, INT_MIN, INT_MAX),
 	PORT_ITEM_INT("inhibit_announce", 0, 0, 1),
-	PORT_ITEM_INT("inhibit_multicast_service", 0, 0, 1),
 	GLOB_ITEM_INT("initial_delay", 0, 0, INT_MAX),
+	PORT_ITEM_INT("inhibit_delay_req", 0, 0, 1),
+	PORT_ITEM_INT("inhibit_multicast_service", 0, 0, 1),
 	GLOB_ITEM_INT("kernel_leap", 1, 0, 1),
 	PORT_ITEM_INT("logAnnounceInterval", 1, INT8_MIN, INT8_MAX),
 	PORT_ITEM_INT("logMinDelayReqInterval", 0, INT8_MIN, INT8_MAX),
diff --git a/configs/automotive-master.cfg b/configs/automotive-master.cfg
index e3ad5a3..2edee76 100644
--- a/configs/automotive-master.cfg
+++ b/configs/automotive-master.cfg
@@ -26,3 +26,4 @@ BMCA			noop
 masterOnly		1
 inhibit_announce	1
 asCapable               true
+inhibit_delay_req       1
diff --git a/configs/default.cfg b/configs/default.cfg
index 2433553..e23dfd7 100644
--- a/configs/default.cfg
+++ b/configs/default.cfg
@@ -37,6 +37,7 @@ G.8275.portDS.localPriority	128
 asCapable               auto
 BMCA                    ptp
 inhibit_announce        0
+inhibit_pdelay_req      0
 ignore_source_id        0
 #
 # Run time options
diff --git a/port.c b/port.c
index 0aaf846..5a4a116 100644
--- a/port.c
+++ b/port.c
@@ -1056,6 +1056,10 @@ int port_set_announce_tmo(struct port *p)
 
 int port_set_delay_tmo(struct port *p)
 {
+	if (p->inhibit_delay_req) {
+		return 0;
+	}
+
 	if (p->delayMechanism == DM_P2P) {
 		return set_tmo_log(p->fda.fd[FD_DELAY_TIMER], 1,
 			       p->logPdelayReqInterval);
@@ -1657,6 +1661,12 @@ int port_initialize(struct port *p)
 		p->asCapable = NOT_CAPABLE;
 	}
 
+	p->inhibit_delay_req = config_get_int(cfg, p->name, "inhibit_delay_req");
+	if (p->inhibit_delay_req && p->asCapable != ALWAYS_CAPABLE) {
+		pr_err("inhibit_delay_req can only be set when asCapable == 'true'.");
+		return -1;
+	}
+
 	for (i = 0; i < N_TIMER_FDS; i++) {
 		fd[i] = -1;
 	}
diff --git a/port_private.h b/port_private.h
index bb1d86e..9a5022d 100644
--- a/port_private.h
+++ b/port_private.h
@@ -100,6 +100,7 @@ struct port {
 	int bmca;
 	int inhibit_announce;
 	int ignore_source_id;
+	int inhibit_delay_req;
 	/* portDS */
 	struct PortIdentity portIdentity;
 	enum port_state     state; /*portState*/
diff --git a/ptp4l.8 b/ptp4l.8
index df7da82..1a01108 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -186,6 +186,11 @@ the interval specified by this config option after the interval_update_timer
 expires. It's specified as a power of two in seconds. The default value is 0 (1
 second).
 .TP
+.B inhibit_delay_req
+Don't send any delay requests. This will need the asCapable config option to be
+set to 'true'. This is useful when running as a designated master who does not
+need to calculate offset from slave. The default is 0 (disabled).
+.TP
 .B announceReceiptTimeout
 The number of missed Announce messages before the last Announce messages
 expires.