From bbb7479baba6fe58a02aee0898777cbdb0c9005b Mon Sep 17 00:00:00 2001 From: Ramesh Gowda Date: Thu, 12 Oct 2023 15:26:27 +0530 Subject: [PATCH] Problem: Under GNSS error condition/fluctuation, ts2phc updating 1sec time into PHC resulting in wrong time. This issue of 1sec jump is seen momentarily. Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.611] nmea delay: 89943030 ns Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.611] enp81s0f0 extts index 0 at 1678461497.000000000 corr 0 src 1678461498.844774711 diff -1000000000 Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.611] enp81s0f0 master offset -1000000000 s2 freq -100000000 Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.612] nmea delay: 89943030 ns Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.612] enp138s0f0 extts index 0 at 1678461497.000000000 corr 0 src 1678461498.845574965 diff -1000000000 Mar 10 15:17:40 sno-cluster-nrnl04-master1 ts2phc: [161756.612] enp138s0f0 master offset -1000000000 s2 freq -100000000 Fix: Defined new configurable skip count variable. Under normal condition ts2phc time diff will be around +-1 nsec. During problem condition ts2phc time diff will be around 1 sec. With servo in SERVO_LOCKED state and ts2phc time diff is more than 500 millsecond, will skip update of PHC for configured skip count value. --- ts2phc.c | 3 +++ ts2phc_slave.c | 23 +++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/ts2phc.c b/ts2phc.c index 2342858..5687c9b 100644 --- a/ts2phc.c +++ b/ts2phc.c @@ -15,6 +15,8 @@ #include "ts2phc_slave.h" #include "version.h" +int max_phc_update_skip_count; + struct interface { STAILQ_ENTRY(interface) list; }; @@ -146,6 +148,7 @@ int main(int argc, char *argv[]) print_set_verbose(config_get_int(cfg, NULL, "verbose")); print_set_syslog(config_get_int(cfg, NULL, "use_syslog")); print_set_level(config_get_int(cfg, NULL, "logging_level")); + max_phc_update_skip_count = config_get_int(cfg, NULL, "max_phc_update_skip_cnt"); STAILQ_FOREACH(iface, &cfg->interfaces, list) { if (1 == config_get_int(cfg, interface_name(iface), "ts2phc.master")) { diff --git a/ts2phc_slave.c b/ts2phc_slave.c index 749efe5..6af1aeb 100644 --- a/ts2phc_slave.c +++ b/ts2phc_slave.c @@ -29,6 +29,8 @@ #define SAMPLE_WEIGHT 1.0 #define SERVO_SYNC_INTERVAL 1.0 +extern int max_phc_update_skip_count; + struct ts2phc_slave { char *name; STAILQ_ENTRY(ts2phc_slave) list; @@ -42,6 +44,8 @@ struct ts2phc_slave { clockid_t clk; int no_adj; int fd; + int max_offset_skip_count; + int current_offset_skip_count; }; struct ts2phc_slave_array { @@ -219,6 +223,10 @@ static struct ts2phc_slave *ts2phc_slave_create(struct config *cfg, const char * goto no_ext_ts; } + slave->max_offset_skip_count = max_phc_update_skip_count; + slave->current_offset_skip_count = 0; + pr_debug("PHC slave %s has skip cnt %d", device, slave->max_offset_skip_count); + return slave; no_ext_ts: no_pin_func: @@ -278,6 +286,17 @@ static int ts2phc_slave_event(struct ts2phc_slave *slave, adj = servo_sample(slave->servo, offset, extts_ts, SAMPLE_WEIGHT, &slave->state); + if ((slave->state == SERVO_LOCKED) || (slave->state == SERVO_LOCKED_STABLE)) { + if (llabs(offset) >= NS_PER_SEC / 2) { + if (slave->current_offset_skip_count < slave->max_offset_skip_count) { + pr_debug("Skip current PHC update %s offset %10" PRId64 " s%d freq %+7.0f", + slave->name, offset, slave->state, adj); + slave->current_offset_skip_count++; + return 0; + } + } + } + pr_debug("%s master offset %10" PRId64 " s%d freq %+7.0f", slave->name, offset, slave->state, adj); @@ -290,6 +309,10 @@ static int ts2phc_slave_event(struct ts2phc_slave *slave, break; case SERVO_LOCKED: case SERVO_LOCKED_STABLE: + if (llabs(offset) < 500) { + slave->current_offset_skip_count = 0; + } + clockadj_set_freq(slave->clk, -adj); break; } -- 2.20.1