diff options
| -rw-r--r-- | networking/ntpd.c | 44 |
1 files changed, 33 insertions, 11 deletions
diff --git a/networking/ntpd.c b/networking/ntpd.c index 17e5c7da6..2754170c0 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -165,8 +165,12 @@ * Using exact power of 2 (1/8) results in smaller code */ #define SLEW_THRESHOLD 0.125 +//^^^^^^^^^^^^^^^^^^^^^^^^^^ TODO: man adjtimex about tmx.offset: +// "Since Linux 2.6.26, the supplied value is clamped to the range (-0.5s, +0.5s)" +// - can use this larger value instead? + /* Stepout threshold (sec). std ntpd uses 900 (11 mins (!)) */ -#define WATCH_THRESHOLD 128 +//UNUSED: #define WATCH_THRESHOLD 128 /* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ //UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */ @@ -419,6 +423,7 @@ struct globals { uint8_t discipline_state; // doc calls it c.state uint8_t poll_exp; // s.poll int polladj_count; // c.count + int FREQHOLD_cnt; long kernel_freq_drift; peer_t *last_update_peer; double last_update_offset; // c.last @@ -1034,6 +1039,7 @@ step_time(double offset) tval = tvn.tv_sec; strftime_YYYYMMDDHHMMSS(buf, sizeof(buf), &tval); bb_error_msg("setting time to %s.%06u (offset %+fs)", buf, (unsigned)tvn.tv_usec, offset); + //maybe? G.FREQHOLD_cnt = 0; /* Correct various fields which contain time-relative values: */ @@ -1709,6 +1715,28 @@ update_local_clock(peer_t *p) tmx.freq = G.discipline_freq_drift * 65536e6; #endif tmx.modes = ADJ_OFFSET | ADJ_STATUS | ADJ_TIMECONST;// | ADJ_MAXERROR | ADJ_ESTERROR; + tmx.status = STA_PLL; + if (G.FREQHOLD_cnt != 0) { + G.FREQHOLD_cnt--; + /* man adjtimex on STA_FREQHOLD: + * "Normally adjustments made via ADJ_OFFSET result in dampened + * frequency adjustments also being made. + * This flag prevents the small frequency adjustment from being + * made when correcting for an ADJ_OFFSET value." + * + * Use this flag for a few first adjustments at the beginning + * of ntpd execution, otherwise even relatively small initial + * offset tend to cause largish changes to in-kernel tmx.freq. + * If ntpd was restarted due to e.g. switch to another network, + * this destroys already well-established tmx.freq value. + */ + tmx.status |= STA_FREQHOLD; + } + if (G.ntp_status & LI_PLUSSEC) + tmx.status |= STA_INS; + if (G.ntp_status & LI_MINUSSEC) + tmx.status |= STA_DEL; + tmx.constant = (int)G.poll_exp - 4; /* EXPERIMENTAL. * The below if statement should be unnecessary, but... @@ -1722,25 +1750,18 @@ update_local_clock(peer_t *p) */ if (G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE) tmx.constant--; + if (tmx.constant < 0) + tmx.constant = 0; + tmx.offset = (long)(offset * 1000000); /* usec */ if (SLEW_THRESHOLD < STEP_THRESHOLD) { if (tmx.offset > (long)(SLEW_THRESHOLD * 1000000)) { tmx.offset = (long)(SLEW_THRESHOLD * 1000000); - tmx.constant--; } if (tmx.offset < -(long)(SLEW_THRESHOLD * 1000000)) { tmx.offset = -(long)(SLEW_THRESHOLD * 1000000); - tmx.constant--; } } - if (tmx.constant < 0) - tmx.constant = 0; - - tmx.status = STA_PLL; - if (G.ntp_status & LI_PLUSSEC) - tmx.status |= STA_INS; - if (G.ntp_status & LI_MINUSSEC) - tmx.status |= STA_DEL; //tmx.esterror = (uint32_t)(clock_jitter * 1e6); //tmx.maxerror = (uint32_t)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); @@ -2227,6 +2248,7 @@ static NOINLINE void ntp_init(char **argv) if (BURSTPOLL != 0) G.poll_exp = BURSTPOLL; /* speeds up initial sync */ G.last_script_run = G.reftime = G.last_update_recv_time = gettime1900d(); /* sets G.cur_time too */ + G.FREQHOLD_cnt = 8; /* Parse options */ peers = NULL; |