From a3c32b8c6561a6579f4ba5cb854798195c8ffd27 Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Wed, 18 Jun 2014 15:44:48 +0200
Subject: [PATCH] phc2sys: track sync offset and leap second status in each
 clock.

This simplifies passing of pending leap seconds to the clocks and it
will also allow to apply leap second to other clocks than system clock
if needed in future.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
---
 phc2sys.c | 54 +++++++++++++++++++++++-------------------------------
 1 file changed, 23 insertions(+), 31 deletions(-)

diff --git a/phc2sys.c b/phc2sys.c
index 26317dc..62a51bd 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -76,6 +76,8 @@ struct clock {
 	int dest_only;
 	int state;
 	int new_state;
+	int sync_offset;
+	int leap_set;
 	struct servo *servo;
 	enum servo_state servo_state;
 	char *device;
@@ -102,7 +104,6 @@ struct node {
 	int sync_offset;
 	int forced_sync_offset;
 	int leap;
-	int leap_set;
 	int kernel_leap;
 	struct pmc *pmc;
 	int pmc_ds_requested;
@@ -117,7 +118,7 @@ struct node {
 
 static int update_pmc(struct node *node, int subscribe);
 static int clock_handle_leap(struct node *node, struct clock *clock,
-			     int64_t offset, uint64_t ts, int do_leap);
+			     int64_t offset, uint64_t ts);
 static int run_pmc_get_utc_offset(struct node *node, int timeout);
 static void run_pmc_events(struct node *node);
 
@@ -389,7 +390,7 @@ static int64_t get_sync_offset(struct node *node, struct clock *dst)
 
 	if (!direction)
 		direction = dst->is_utc - node->master->is_utc;
-	return (int64_t)node->sync_offset * NS_PER_SEC * direction;
+	return (int64_t)dst->sync_offset * NS_PER_SEC * direction;
 }
 
 static void update_clock_stats(struct clock *clock, unsigned int max_count,
@@ -428,13 +429,12 @@ static void update_clock_stats(struct clock *clock, unsigned int max_count,
 }
 
 static void update_clock(struct node *node, struct clock *clock,
-			 int64_t offset, uint64_t ts, int64_t delay,
-			 int do_leap)
+			 int64_t offset, uint64_t ts, int64_t delay)
 {
 	enum servo_state state;
 	double ppb;
 
-	if (clock_handle_leap(node, clock, offset, ts, do_leap))
+	if (clock_handle_leap(node, clock, offset, ts))
 		return;
 
 	offset += get_sync_offset(node, clock);
@@ -513,7 +513,6 @@ static int do_pps_loop(struct node *node, struct clock *clock, int fd)
 	int64_t pps_offset, phc_offset, phc_delay;
 	uint64_t pps_ts, phc_ts;
 	clockid_t src = node->master->clkid;
-	int do_leap;
 
 	node->master->source_label = "pps";
 
@@ -550,10 +549,9 @@ static int do_pps_loop(struct node *node, struct clock *clock, int fd)
 			pps_offset = pps_ts - phc_ts;
 		}
 
-		do_leap = update_pmc(node, 0);
-		if (do_leap < 0)
+		if (update_pmc(node, 0) < 0)
 			continue;
-		update_clock(node, clock, pps_offset, pps_ts, -1, do_leap);
+		update_clock(node, clock, pps_offset, pps_ts, -1);
 	}
 	close(fd);
 	return 0;
@@ -565,15 +563,13 @@ static int do_loop(struct node *node, int subscriptions)
 	struct clock *clock;
 	uint64_t ts;
 	int64_t offset, delay;
-	int do_leap;
 
 	interval.tv_sec = node->phc_interval;
 	interval.tv_nsec = (node->phc_interval - interval.tv_sec) * 1e9;
 
 	while (1) {
 		clock_nanosleep(CLOCK_MONOTONIC, 0, &interval, NULL);
-		do_leap = update_pmc(node, subscriptions);
-		if (do_leap < 0)
+		if (update_pmc(node, subscriptions) < 0)
 			continue;
 
 		if (subscriptions) {
@@ -609,7 +605,7 @@ static int do_loop(struct node *node, int subscriptions)
 					      &offset, &ts, &delay))
 					continue;
 			}
-			update_clock(node, clock, offset, ts, delay, do_leap);
+			update_clock(node, clock, offset, ts, delay);
 		}
 	}
 	return 0; /* unreachable */
@@ -1048,12 +1044,11 @@ static int auto_init_ports(struct node *node, int add_rt)
 	return 0;
 }
 
-/* Returns: -1 in case of error, 0 for normal sync, 1 to leap clock */
+/* Returns: -1 in case of error, 0 otherwise */
 static int update_pmc(struct node *node, int subscribe)
 {
 	struct timespec tp;
 	uint64_t ts;
-	int clock_leap;
 
 	if (clock_gettime(CLOCK_REALTIME, &tp)) {
 		pr_err("failed to read clock: %m");
@@ -1070,25 +1065,18 @@ static int update_pmc(struct node *node, int subscribe)
 			node->pmc_last_update = ts;
 	}
 
-	/* Handle leap seconds. */
-
-	if (!node->leap && !node->leap_set)
-		return 0;
-
-	clock_leap = leap_second_status(ts, node->leap_set,
-					&node->leap, &node->sync_offset);
-	if (node->leap_set != clock_leap) {
-		node->leap_set = clock_leap;
-		return 1;
-	}
 	return 0;
 }
 
 /* Returns: non-zero to skip clock update */
 static int clock_handle_leap(struct node *node, struct clock *clock,
-			     int64_t offset, uint64_t ts, int do_leap)
+			     int64_t offset, uint64_t ts)
 {
-	if (!node->leap && !do_leap)
+	int clock_leap, node_leap = node->leap;
+
+	clock->sync_offset = node->sync_offset;
+
+	if (!node_leap && !clock->leap_set)
 		return 0;
 
 	if (clock->is_utc == node->master->is_utc)
@@ -1116,10 +1104,14 @@ static int clock_handle_leap(struct node *node, struct clock *clock,
 		return 1;
 	}
 
-	if (do_leap) {
+	clock_leap = leap_second_status(ts, clock->leap_set,
+					&node_leap, &clock->sync_offset);
+
+	if (clock->leap_set != clock_leap) {
 		/* Only the system clock can leap. */
 		if (clock->clkid == CLOCK_REALTIME && node->kernel_leap)
-			sysclk_set_leap(node->leap_set);
+			sysclk_set_leap(clock_leap);
+		clock->leap_set = clock_leap;
 	}
 
 	return 0;