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hardpps() wants the raw hardware counter value converted to nanoseconds.

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jhay 2003-01-16 19:22:13 +00:00
parent ef30ad92ed
commit d24749bcb4
1 changed files with 7 additions and 7 deletions
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14
sys/kern/kern_tc.c
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@ -561,6 +561,7 @@ pps_event(struct pps_state *pps, int event)
{
struct bintime bt;
struct timespec ts, *tsp, *osp;
u_int64_t scale;
u_int tcount, *pcount;
int foff, fhard;
pps_seq_t *pseq;
@ -628,19 +629,18 @@ pps_event(struct pps_state *pps, int event)
if (fhard) {
/*
* Feed the NTP PLL/FLL.
* The FLL wants to know how many nanoseconds elapsed since
* the previous event.
* I have never been able to convince myself that this code
* is actually correct: Using th_scale is bound to contain
* a phase correction component from userland, when running
* as FLL, so the number hardpps() gets is not meaningful IMO.
* The FLL wants to know how many (hardware) nanoseconds
* elapsed since the previous event.
*/
tcount = pps->capcount - pps->ppscount[2];
pps->ppscount[2] = pps->capcount;
tcount &= pps->capth->th_counter->tc_counter_mask;
scale = (u_int64_t)1 << 63;
scale /= pps->capth->th_counter->tc_frequency;
scale *= 2;
bt.sec = 0;
bt.frac = 0;
bintime_addx(&bt, pps->capth->th_scale * tcount);
bintime_addx(&bt, scale * tcount);
bintime2timespec(&bt, &ts);
hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec);
}