ntp does not synchronize on an AMD 5700G system

[Peter Jansen]

On an AMD 5700G system, NTP does NOT synchronize :

hercules@pjamdz3a:~$ timedatectl
               Local time: Thu 2021-11-04 12:57:24 CET
           Universal time: Thu 2021-11-04 11:57:24 UTC
                 RTC time: Thu 2021-11-04 11:57:44
                Time zone: Europe/Zurich (CET, +0100)
System clock synchronized: no
              NTP service: n/a
          RTC in local TZ: no
hercules@pjamdz3a:~$ ntpq -p
     remote refid st t when poll reach delay offset jitter
==============================================================================
 pjjrpiz.pj.org .PPS. 1 u 11 64 377 0.574 19761.2 2151.25
 time2.ethz.ch .PPS. 1 u 16 64 377 12.743 19729.7 2132.80
hercules@pjamdz3a:~$ apt-cache policy ntp chrony systemd-timesyncd
ntp:
  Installed: 1:4.2.8p12+dfsg-3ubuntu4.20.04.1
  Candidate: 1:4.2.8p12+dfsg-3ubuntu4.20.04.1
  Version table:
 *** 1:4.2.8p12+dfsg-3ubuntu4.20.04.1 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages
        100 /var/lib/dpkg/status
     1:4.2.8p12+dfsg-3ubuntu4 500
        500 http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages
chrony:
  Installed: (none)
  Candidate: 3.5-6ubuntu6.2
  Version table:
     3.5-6ubuntu6.2 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
        100 /var/lib/dpkg/status
     3.5-6ubuntu6 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
systemd-timesyncd:
  Installed: (none)
  Candidate: 245.4-4ubuntu3.13
  Version table:
     245.4-4ubuntu3.13 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     245.4-4ubuntu3.11 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     245.4-4ubuntu3 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
hercules@pjamdz3a:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
hercules@pjamdz3a:~$

But on a nearly identical Intel based system, (as well as on a Raspberry Pi 20.04 or an Ubuntu 18.04 system), there are no problems whatsoever :

hercules@pjlu2004:~$ timedatectl
               Local time: Thu 2021-11-04 12:55:10 CET
           Universal time: Thu 2021-11-04 11:55:10 UTC
                 RTC time: Thu 2021-11-04 11:55:10
                Time zone: Europe/Zurich (CET, +0100)
System clock synchronized: yes
              NTP service: n/a
          RTC in local TZ: no
hercules@pjlu2004:~$ ntpq -p
     remote refid st t when poll reach delay offset jitter
==============================================================================
*pjjrpiz.pj.org .PPS. 1 u 32 64 377 0.532 4.204 2.957
+time2.ethz.ch .PPS. 1 u 4 64 377 11.703 9.206 2.164
hercules@pjlu2004:~$ apt-cache policy ntp chrony systemd-timesyncd
ntp:
  Installed: 1:4.2.8p12+dfsg-3ubuntu4.20.04.1
  Candidate: 1:4.2.8p12+dfsg-3ubuntu4.20.04.1
  Version table:
 *** 1:4.2.8p12+dfsg-3ubuntu4.20.04.1 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages
        100 /var/lib/dpkg/status
     1:4.2.8p12+dfsg-3ubuntu4 500
        500 http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages
chrony:
  Installed: (none)
  Candidate: 3.5-6ubuntu6.2
  Version table:
     3.5-6ubuntu6.2 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     3.5-6ubuntu6 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
systemd-timesyncd:
  Installed: (none)
  Candidate: 245.4-4ubuntu3.13
  Version table:
     245.4-4ubuntu3.13 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     245.4-4ubuntu3.11 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     245.4-4ubuntu3.3 -1
        100 /var/lib/dpkg/status
     245.4-4ubuntu3 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
hercules@pjlu2004:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
hercules@pjlu2004:~$

I have been searching the 'net, and tried a number of alternatives (e.g. chrony and systemd-timesyncd), but none of them are good alternatives. Please note that "pjjrpiz.pj.org" is a self built in-house GPS based NTP server running on yet another Raspberry Pi.

Any support you may be able to offer will be appreciated ! if there are any other tests or actions you would like me to take to try fixing this annoying problem, probably only on this AMD 5700G CPU based system (in an ASUS Desktop X300M system), please just ask.

Thanks for all your efforts.

Peter J. Jansen
Fichtlirain 13
CH-4105 Biel-Benken
Switzerland

Mob.: [phone]
E-Mail (IEEE Life Member) : <email address hidden>
E-Mail (S/MIME signed) : <email address hidden>

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ntp 1:4.2.8p12+dfsg-3ubuntu4.20.04.1
ProcVersionSignature: Ubuntu 5.11.0-38.42~20.04.1-generic 5.11.22
Uname: Linux 5.11.0-38-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: LXQt
Date: Thu Nov 4 13:07:22 2021
InstallationDate: Installed on 2021-09-04 (61 days ago)
InstallationMedia: Lubuntu 20.04.3 LTS "Focal Fossa" - Release amd64 (20210819)
NtpStatus:
 remote refid st t when poll reach delay offset jitter
 ==============================================================================
  pjjrpiz.pj.org .PPS. 1 u 11 64 377 0.465 24032.5 2120.23
  time2.ethz.ch .PPS. 1 u 12 64 177 11.307 24028.7 2386.31
SourcePackage: ntp
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.ntp.conf: [modified]
mtime.conffile..etc.ntp.conf: 2021-11-01T10:08:38.252598

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sambit Bikas Pal (sambitbikaspal)]

Encountering same issue on a total of 9 workstations with AMD 5700G processor. Other workstations based on 5700X and 3800X can syncronise from same NTP source without issues.