Re: [chrony-users] PHC / NIC / PPS mismatch

[Christopher Hoover <ch@xxxxxxxxxxxxxx>]

OK, did dist upgrade to Debian 11 (bullseye) on this working system.

christopher@apu-42:~$ dpkg -l |grep chrony
ii  chrony                           4.0-8
amd64        Versatile implementation of the Network Time Protocol
christopher@apu-42:~$ uname -a
Linux apu-42 5.10.0-9-amd64 #1 SMP Debian 5.10.70-1 (2021-09-30)
x86_64 GNU/Linux
christopher@apu-42:~$

Same config, except I have  to change ,pin=0 to :pin=0 to get chrony
to start.    No bueno.  Doesn't see the edge from the GPS.

nptshmon is showing results.

If I remove :pin=0 entirely, no difference.


Summary:

Debian 10 / chrony 3.4-4+deb10u1 no pin / linux 4.19   => DOES NOT WORK
Debian 10 / chrony 3.4-4+deb10u1 ,pin=0 / linux 4.19   => WORKS
Debian 10 / chrony 3.4-4+deb10u1 ,pin=0 / linux 5.10.0 => WORKS
Debian 11 / chrony 4.0 / linux 5.10.0 :pin=0  => DOES NOT WORK
Debian 11 / chrony 4.0 / linux 5.10.0 no pin  => DOES NOT WORK

-- Christopher.



On Wed, Nov 17, 2021 at 8:25 PM Christopher Hoover <ch@xxxxxxxxxxxxxx> wrote:
>
> It doesn't seem to be the 5.10 kernel alone.   I did a clean Debian 10
> and made it work.  That's chrony 3.44 and Linux 4.19.0.
>
> Then I used backports to install a 5.10.0 kernel.   Reboot.   It still works:
>
> christopher@apu-42:~$ chronyc sources; echo; chronyc sourcestats;
> echo; chronyc tracking
> 210 Number of sources = 6
> MS Name/IP address         Stratum Poll Reach LastRx Last sample
> ===============================================================================
> #? NMEA                          0   3   377     8    +92ms[  +92ms] +/- 1710us
> #* PPS                           0   0   377     0    +16ns[  +19ns] +/-  121ns
> ^? 2600:3c01::f03c:91ff:feb>     0   6     0     -     +0ns[   +0ns] +/-    0ns
> ^x 12.167.151.1                  3   6   373    15   +114ms[ +114ms] +/-  100ms
> ^x 208.67.72.50                  2   6   377    14   +112ms[ +112ms] +/-   80ms
> ^x ns2.iu13.org                  2   6   377    13   +101ms[ +101ms] +/-   68ms
>
> 210 Number of sources = 6
> Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
> ==============================================================================
> NMEA                        6   4    41   +200.359    662.364    +97ms  1545us
> PPS                         6   4     5     +0.004      0.012     +1ns     6ns
> 2600:3c01::f03c:91ff:feb>   0   0     0     +0.000   2000.000     +0ns  4000ms
> 12.167.151.1               14   7   716     -6.102      0.790   +114ms   177us
> 208.67.72.50               15   6   718     -6.428      0.824   +112ms   166us
> ns2.iu13.org               15   7   719     -6.649      2.613   +101ms   555us
>
> Reference ID    : 50505300 (PPS)
> Stratum         : 1
> Ref time (UTC)  : Thu Nov 18 03:29:14 2021
> System time     : 0.000000008 seconds fast of NTP time
> Last offset     : +0.000000013 seconds
> RMS offset      : 0.000000006 seconds
> Frequency       : 0.269 ppm slow
> Residual freq   : +0.004 ppm
> Skew            : 0.006 ppm
> Root delay      : 0.000000001 seconds
> Root dispersion : 0.000001043 seconds
> Update interval : 1.0 seconds
> Leap status     : Normal
> christopher@apu-42:~$ cat /etc/chrony/chrony.conf
> keyfile /etc/chrony/chrony.keys
> driftfile /var/lib/chrony/chrony.drift
> logdir /var/log/chrony
>
> maxupdateskew 100.0
> rtcsync
> makestep 1 3
>
> pool 2.debian.pool.ntp.org iburst
>
>
> hwtimestamp enp1s0
> refclock SHM 0 refid NMEA precision 1e-3 poll 3 offset 100e-3 noselect
> refclock PHC /dev/ptp3:extpps,pin=0 refid PPS width 100e-3 poll 0 lock
> NMEA trust
> christopher@apu-42:~$ uname -a
> Linux apu-42 5.10.0-0.bpo.9-amd64 #1 SMP Debian 5.10.70-1~bpo10+1
> (2021-10-10) x86_64 GNU/Linux
> christopher@apu-42:~$ dpkg -l chrony
> Desired=Unknown/Install/Remove/Purge/Hold
> | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
> |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
> ||/ Name           Version       Architecture Description
> +++-==============-=============-============-===========================================
> ii  chrony         3.4-4+deb10u1 amd64        Versatile implementation
> of the Network Tim
> christopher@apu-42:~$
>
>
>
>
> On Mon, Nov 15, 2021 at 7:57 PM Christopher Hoover <ch@xxxxxxxxxxxxxx> wrote:
> >
> > p.s. in all cases ntpshmon shows data:
> >
> > christopher@apu-42:~$ sudo ntpshmmon
> > ntpshmmon: version 3.22
> > #      Name  Seen@                 Clock                 Real                 L Prc
> > sample NTP0  1637034947.292044404  1637034947.090644472  1637034947.000278692 0 -20
> > sample NTP0  1637034948.110421061  1637034948.109557612  1637034948.000278696 0 -20
> >
> > (this is the deb 11 box that doesn't see PPS on the NIC at all.)
> >
> > -- Christopher.
> >
> >
> >
> > On Mon, Nov 15, 2021 at 7:44 PM Christopher Hoover <ch@xxxxxxxxxxxxxx> wrote:
> >>
> >> I upgraded the 4-nic box to Debian 11.
> >>
> >> kernel 5.10.0-9-amd64 #1 SMP Debian 5.10.70-1
> >> chrony 4.0-8
> >>
> >> Using same config file that work under Debian 10, startup fails because of the comma in
> >>
> >> ---
> >> refclock PHC /dev/ptp3:extpps,pin=0 refid PPS width 100e-3 precision 1e-9 poll 0 lock NMEA trust
> >> ---
> >>
> >> Changing the comma do colon does not work (reflock PPS sees nothing).
> >>
> >> I dropped the "lock NMEA trust":
> >>
> >> ---
> >> refclock PHC /dev/ptp3:extpps refid PPS width 100e-3 precision 1e-9 poll 0
> >> ---
> >>
> >> no pin does not work (reflock PPS sees nothing)
> >> :pin=0 does not work (reflock PPS sees nothing)
> >> :pin=1 does not work (reflock PPS sees nothing)
> >>
> >> I suppose I can reinstall Debian 10 and roll the kernel to 5.x with backports.
> >>
> >> -- Christopher
> >>
> >>
> >>
> >>
> >> On Mon, Nov 15, 2021 at 6:31 PM Christopher Hoover <ch@xxxxxxxxxxxxxx> wrote:
> >>>
> >>> This works on the 4 NIC board:
> >>>
> >>> ---
> >>> refclock PHC /dev/ptp3:extpps,pin=0 refid PPS width 100e-3 precision 1e-9 poll 0 lock NMEA trust
> >>> ---
> >>>
> >>> but without ",pin=0", it does not.
> >>>
> >>>
> >>> On nearly identical hardware, difference being  3 NICs ( PPS wired to the 'last' NIC in both cases),  this works fine:
> >>>
> >>> ---
> >>> refclock PHC /dev/ptp2:extpps refid PPS width 100e-3 precision 1e-9 poll 0 lock NMEA trust
> >>> ---
> >>>
> >>> Same kernel (4.19.0-18-amd64 #1 SMP Debian 4.19.208-1).     Same chrony (3.4-4+deb10u1).
> >>>
> >>> I'll roll the kernel forward and chrony forward from Debian 10 to Debian 11 and report results.
> >>>
> >>> -- Christopher.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> On Mon, Nov 15, 2021 at 12:54 AM Miroslav Lichvar <mlichvar@xxxxxxxxxx> wrote:
> >>>>
> >>>> On Fri, Nov 12, 2021 at 05:28:56PM -0800, Christopher Hoover wrote:
> >>>> > refclock SHM 0 refid NMEA precision 1e-3 poll 3 offset 100e-3 noselect
> >>>> > refclock PHC /dev/ptp2:extpps refid PPS width 100e-3 precision 1e-9 lock
> >>>> > NMEA poll 0 trust
> >>>>
> >>>> > If I look for PPS, I find it on ptp0/pps0 with Bullseye.
> >>>>
> >>>> > It is not found anywhere else.
> >>>> >
> >>>> > If tried telling chrony to /dev/ptp0 instead of /dev/ptp2, but it does NOT
> >>>> > find the PPS.
> >>>>
> >>>> Does the SHM refclock work correctly? If it didn't, the PPS PHC
> >>>> wouldn't report any samples. You could try removing the lock option
> >>>> and add an NTP server to be sure.
> >>>>
> >>>> I don't remember any changes between chrony-3.4 and 4.0 that could
> >>>> have an impact in this configuration.
> >>>>
> >>>> You could try adding ":pin=1" to the PHC refclock config, to see if
> >>>> the newer kernel is numbering the pins differently, but I doubt it.
> >>>>
> >>>> If that doesn't help, run chronyd in strace for few seconds and post
> >>>> the output here.
> >>>>
> >>>> --
> >>>> Miroslav Lichvar
> >>>>
> >>>>
> >>>> --
> >>>> To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
> >>>> with "unsubscribe" in the subject.
> >>>> For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
> >>>> with "help" in the subject.
> >>>> Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.
> >>>>

-- 
To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx 
with "help" in the subject.
Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.