chao
/
linuxptp
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ptp4l: Handle leap seconds. 

Extend the clock_utc_correct function to handle leap seconds announced
in the time properties data set. With software time stamping, it sets the
STA_INS/STA_DEL bit for the system clock. Clock updates are suspended
in the last second of the day.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
master
Miroslav Lichvar 2013-03-07 17:27:32 +01:00 committed by Richard Cochran
parent 09667479b8
commit e21af97091
1 changed files with 62 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
clock.c
View File

@ -78,6 +78,8 @@ struct clock {
int free_running;
int freq_est_interval;
int utc_timescale;
int leap_set;
enum servo_state servo_state;
tmv_t master_offset;
tmv_t path_delay;
struct mave *avg_delay;
@ -449,23 +451,66 @@ static void clock_update_slave(struct clock *c)
}
}
static void clock_utc_correct(struct clock *c)
static int clock_utc_correct(struct clock *c, tmv_t ingress)
{
struct timespec offset;
int utc_offset, leap, clock_leap;
uint64_t ts;
if (!c->utc_timescale)
return;
if (!(c->tds.flags & PTP_TIMESCALE))
return;
return 0;
if (c->tds.flags & UTC_OFF_VALID && c->tds.flags & TIME_TRACEABLE) {
offset.tv_sec = c->tds.currentUtcOffset;
utc_offset = c->tds.currentUtcOffset;
} else if (c->tds.currentUtcOffset > CURRENT_UTC_OFFSET) {
offset.tv_sec = c->tds.currentUtcOffset;
utc_offset = c->tds.currentUtcOffset;
} else {
offset.tv_sec = CURRENT_UTC_OFFSET;
utc_offset = CURRENT_UTC_OFFSET;
}
if (c->tds.flags & LEAP_61) {
leap = 1;
} else if (c->tds.flags & LEAP_59) {
leap = -1;
} else {
leap = 0;
}
/* Handle leap seconds. */
if ((leap || c->leap_set) && c->clkid == CLOCK_REALTIME) {
/* If the clock will be stepped, the time stamp has to be the
target time. Ignore possible 1 second error in utc_offset. */
if (c->servo_state == SERVO_UNLOCKED) {
ts = tmv_to_nanoseconds(tmv_sub(ingress,
c->master_offset));
if (c->tds.flags & PTP_TIMESCALE)
ts -= utc_offset * NS_PER_SEC;
} else {
ts = tmv_to_nanoseconds(ingress);
}
/* Suspend clock updates in the last second before midnight. */
if (is_utc_ambiguous(ts)) {
pr_info("clock update suspended due to leap second");
return -1;
}
clock_leap = leap_second_status(ts, c->leap_set,
&leap, &utc_offset);
if (c->leap_set != clock_leap) {
clockadj_set_leap(c->clkid, clock_leap);
c->leap_set = clock_leap;
}
}
if (!(c->tds.flags & PTP_TIMESCALE))
return 0;
offset.tv_sec = utc_offset;
offset.tv_nsec = 0;
/* Local clock is UTC, but master is TAI. */
c->master_offset = tmv_add(c->master_offset, timespec_to_tmv(offset));
return 0;
}
static int forwarding(struct clock *c, struct port *p)
@ -534,7 +579,10 @@ struct clock *clock_create(int phc_index, struct interface *iface, int count,
c->clkid = CLOCK_REALTIME;
c->utc_timescale = 1;
max_adj = 512000;
clockadj_set_leap(c->clkid, 0);
}
c->leap_set = 0;
c->kernel_leap = dds->kernel_leap;
if (c->clkid != CLOCK_INVALID) {
fadj = (int) clockadj_get_freq(c->clkid);
@ -544,6 +592,7 @@ struct clock *clock_create(int phc_index, struct interface *iface, int count,
pr_err("Failed to create clock servo");
return NULL;
}
c->servo_state = SERVO_UNLOCKED;
c->avg_delay = mave_create(MAVE_LENGTH);
if (!c->avg_delay) {
pr_err("Failed to create moving average");
@ -968,18 +1017,20 @@ enum servo_state clock_synchronize(struct clock *c,
c->master_offset = tmv_sub(ingress,
tmv_add(origin, tmv_add(c->path_delay, tmv_add(c->c1, c->c2))));
clock_utc_correct(c);
c->cur.offsetFromMaster = tmv_to_TimeInterval(c->master_offset);
if (!c->path_delay)
return state;
if (clock_utc_correct(c, ingress))
return c->servo_state;
c->cur.offsetFromMaster = tmv_to_TimeInterval(c->master_offset);
if (c->free_running)
return clock_no_adjust(c);
adj = servo_sample(c->servo, tmv_to_nanoseconds(c->master_offset),
tmv_to_nanoseconds(ingress), &state);
c->servo_state = state;
if (c->stats.max_count > 1) {
clock_stats_update(&c->stats,