From 78aaef8a1abc40ac94182e6c37616d41670ebd19 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Wed, 11 Jun 2014 21:35:14 +0200 Subject: [PATCH] phc2sys: store information about clocks being UTC or TAI For now, only CLOCK_REALTIME can be UTC. This may stay this way forever but now we have a clean separation between codepaths where CLOCK_REALTIME is required and codepaths any UTC clock should take. The main motiviation behind this change is removal of sync_offset_direction. It has to be computed on the fly based on the source and destination when we have multiple clocks supported and automatic following of ptp4l state changes implemented. Signed-off-by: Jiri Benc --- phc2sys.c | 60 +++++++++++++++++++++++++++---------------------------- 1 file changed, 29 insertions(+), 31 deletions(-) diff --git a/phc2sys.c b/phc2sys.c index 825d732..5b1f243 100644 --- a/phc2sys.c +++ b/phc2sys.c @@ -130,6 +130,7 @@ struct clock { LIST_ENTRY(clock) list; clockid_t clkid; int sysoff_supported; + int is_utc; struct servo *servo; enum servo_state servo_state; const char *source_label; @@ -146,7 +147,7 @@ struct node { int phc_readings; double phc_interval; int sync_offset; - int sync_offset_direction; + int forced_sync_offset; int leap; int leap_set; int kernel_leap; @@ -161,6 +162,15 @@ static int update_sync_offset(struct node *node); static int clock_handle_leap(struct node *node, struct clock *clock, int64_t offset, uint64_t ts, int do_leap); +static int64_t get_sync_offset(struct node *node, struct clock *dst) +{ + int direction = node->forced_sync_offset; + + if (!direction) + direction = dst->is_utc - node->master->is_utc; + return (int64_t)node->sync_offset * NS_PER_SEC * direction; +} + static void update_clock_stats(struct clock *clock, unsigned int max_count, int64_t offset, double freq, int64_t delay) { @@ -206,9 +216,7 @@ static void update_clock(struct node *node, struct clock *clock, if (clock_handle_leap(node, clock, offset, ts, do_leap)) return; - if (node->sync_offset_direction) - offset += node->sync_offset * NS_PER_SEC * - node->sync_offset_direction; + offset += get_sync_offset(node, clock); if (clock->sanity_check && clockcheck_sample(clock->sanity_check, ts)) servo_reset(clock->servo); @@ -290,7 +298,7 @@ static int do_pps_loop(struct node *node, struct clock *clock, int fd) if (src == CLOCK_INVALID) { /* The sync offset can't be applied with PPS alone. */ - node->sync_offset_direction = 0; + node->sync_offset = 0; } else { enable_pps_output(node->master->clkid); } @@ -558,15 +566,14 @@ static int clock_handle_leap(struct node *node, struct clock *clock, if (!node->leap && !do_leap) return 0; - if (clock->clkid != CLOCK_REALTIME && - node->master->clkid != CLOCK_REALTIME) + if (clock->is_utc == node->master->is_utc) return 0; /* If the system clock is the master clock, get a time stamp from it, as it is the clock which will include the leap second. */ - if (node->master->clkid == CLOCK_REALTIME) { + if (node->master->is_utc) { struct timespec tp; - if (clock_gettime(CLOCK_REALTIME, &tp)) { + if (clock_gettime(node->master->clkid, &tp)) { pr_err("failed to read clock: %m"); return -1; } @@ -575,11 +582,8 @@ static int clock_handle_leap(struct node *node, struct clock *clock, /* If the clock will be stepped, the time stamp has to be the target time. Ignore possible 1 second error in UTC offset. */ - if (clock->clkid == CLOCK_REALTIME && - clock->servo_state == SERVO_UNLOCKED) { - ts -= offset + node->sync_offset * NS_PER_SEC * - node->sync_offset_direction; - } + if (clock->is_utc && clock->servo_state == SERVO_UNLOCKED) + ts -= offset + get_sync_offset(node, clock); /* Suspend clock updates in the last second before midnight. */ if (is_utc_ambiguous(ts)) { @@ -610,10 +614,12 @@ static int clock_add(struct node *node, clockid_t clkid) c->clkid = clkid; c->servo_state = SERVO_UNLOCKED; - if (c->clkid == CLOCK_REALTIME) + if (c->clkid == CLOCK_REALTIME) { c->source_label = "sys"; - else + c->is_utc = 1; + } else { c->source_label = "phc"; + } if (node->stats_max_count > 0) { c->offset_stats = stats_create(); @@ -698,7 +704,7 @@ int main(int argc, char *argv[]) clockid_t src = CLOCK_INVALID; clockid_t dst = CLOCK_REALTIME; int c, domain_number = 0, pps_fd = -1; - int r, wait_sync = 0, forced_sync_offset = 0; + int r, wait_sync = 0; int print_level = LOG_INFO, use_syslog = 1, verbose = 0; double phc_rate; struct node node = { @@ -779,8 +785,7 @@ int main(int argc, char *argv[]) if (get_arg_val_i(c, optarg, &node.sync_offset, INT_MIN, INT_MAX)) return -1; - node.sync_offset_direction = -1; - forced_sync_offset = 1; + node.forced_sync_offset = -1; break; case 'L': if (get_arg_val_i(c, optarg, &node.sanity_freq_limit, 0, INT_MAX)) @@ -841,7 +846,7 @@ int main(int argc, char *argv[]) goto bad_usage; } - if (!wait_sync && !forced_sync_offset) { + if (!wait_sync && !node.forced_sync_offset) { fprintf(stderr, "time offset must be specified using -w or -O\n"); goto bad_usage; @@ -870,24 +875,17 @@ int main(int argc, char *argv[]) pr_notice("Waiting for ptp4l..."); } - if (!forced_sync_offset) { + if (!node.forced_sync_offset) { r = run_pmc_get_utc_offset(&node, 1000); if (r <= 0) { pr_err("failed to get UTC offset"); return -1; } - - if (src != CLOCK_REALTIME && - dst == CLOCK_REALTIME) - node.sync_offset_direction = 1; - else if (src == CLOCK_REALTIME && - dst != CLOCK_REALTIME) - node.sync_offset_direction = -1; - else - node.sync_offset_direction = 0; } - if (forced_sync_offset || !node.sync_offset_direction) + if (node.forced_sync_offset || + (src != CLOCK_REALTIME && dst != CLOCK_REALTIME) || + src == CLOCK_INVALID) close_pmc(&node); }