ntpsec is ignoring PPS
folkert
folkert at vanheusden.com
Tue Nov 30 19:48:11 UTC 2021
> > server 127.127.22.0 minpoll 1 maxpoll 4 prefer
> > server 127.127.22.1 minpoll 1 maxpoll 4 prefer
>
> You have 2 PPS? Odd.
To compare their results as one is a false-ticker according to ntp.
Initially (and eventually) it will be one - only the gpsdo.
> minpoll 1 is too small. minpoll 3 o4 4 is better.
Ok, changed that.
> > pool nl.pool.ntp.org
> If you look below, you see this is not working. It should put 4
> pool servers into your chimers.
Sorry I did not paste everything:
remote refid st t when poll reach delay offset jitter
oPPS(0) .PPS. 0 l 1 8 377 0.0000 -0.0016 0.0062
xPPS(1) .PPS. 0 l 1 2 377 0.0000 -492.075 0.0045
nl.pool.ntp.org .POOL. 16 p - 256 0 0.0000 0.0000 0.0019
-aardbei.vanderz 193.67.79.202 2 u 37 64 377 16.2151 0.5333 2.4506
*ntp0.bgwlan.nl .PPS. 1 u 14 64 377 23.6166 1.5371 0.8806
-backup.kabelnet 195.238.74.240 3 u 3 64 377 10.4812 0.6105 2.1840
+time.cloudflare 10.20.14.167 3 u 63 64 377 9.3986 1.4638 15.4519
+gowest.hojmark. 131.176.107.13 2 u 60 64 377 8.9020 0.8672 2.5231
+services.freshd 213.136.0.252 2 u 23 64 377 11.4849 2.0886 3.7879
ntp1.mediamatic 192.87.106.2 2 u 58m 1024 0 12.4677 2.6361 0.0000
ntpd ntpsec-1.2.0 2021-06-17T05:15:04Z Updated: 2021-11-30T19:43:59 (1)
lstint avgint rstr r m v count score drop rport remote address
0 0.273 0 . 6 2 3627 2.123 0 34988 localhost
4 66 c0 . 4 4 97 0.052 0 123 backup.kabelnetveendam.nl
15 66 c0 . 4 4 97 0.052 0 123 ntp0.bgwlan.nl
23 67 c0 . 4 4 95 0.052 0 123 services.freshdot.net
38 67 c0 . 4 4 95 0.052 0 123 aardbei.vanderzwet.net
60 66 c0 . 4 4 95 0.052 0 123 gowest.hojmark.net
64 67 c0 . 4 4 95 0.052 0 123 time.cloudflare.com
3467 128 c0 . 4 4 23 0.050 0 123 ntp1.mediamatic.nl
> > and receives PPS events:
> >
> > root at gpsdomonitor:~# strace -tt -fp 826 2>&1 | grep -i PPS
> > 19:33:05.754863 ioctl(4, PPS_FETCH, 0xbef90af8) = 0
> > 19:33:05.758057 ioctl(3, PPS_FETCH, 0xbef90af8) = 0
>
> That proves little. What does this show?
>
> # ppstest /dev/pps0
> # ppstest /dev/pps1
>
> > Also when logging the local clock,
> > /sys/devices/virtual/pps/pps0/assert and
> > /sys/devices/virtual/pps/pps1/assert I see (sane?) values:
>
> That is doing things the hard way.
root at gpsdomonitor:~# ppstest /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1638301439.000018737, sequence: 6855 - clear 0.000000000, sequence: 0
source 0 - assert 1638301440.000019666, sequence: 6856 - clear 0.000000000, sequence: 0
source 0 - assert 1638301441.000007601, sequence: 6857 - clear 0.000000000, sequence: 0
^C
root at gpsdomonitor:~# ppstest /dev/pps1
trying PPS source "/dev/pps1"
found PPS source "/dev/pps1"
ok, found 1 source(s), now start fetching data...
source 0 - assert 1638301442.492104445, sequence: 6858 - clear 0.000000000, sequence: 0
source 0 - assert 1638301443.492092973, sequence: 6859 - clear 0.000000000, sequence: 0
source 0 - assert 1638301444.492091520, sequence: 6860 - clear 0.000000000, sequence: 0
^C
> > ntpq shows:
> > PPS(0) is a regular garmin lvc18, while PPS(1) is a GPS disciplined
> > oscillator, this one:
>
> You prolly should of led with that. The garmin is old and you can get
> way better receivers now for under $20. But, as you showed, they are
> working as expected.
Some more details: this is not the only with a gps connected. This is,
though, the only one with a gpsdo connected (and that garmin as
reference). I'm trying to debug what is wrong with the gpsdo and/or ntp.
The gpsdo only feeds a 1PPS to the pi, so I can't go the gpsd way
> You need to carefullly read and understand this part:
> https://gpsd.io/gpsd-time-service-howto.html#_feeding_ntpd_from_gpsd
I know that text. I should've kept the pool-part for clarity.
regards
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