ModemManager Process is shutting down

[Aleksander Morgado]

Hey,

> Before Logs:
>
> ModemManager[104]: <debug> Signal strength (umts): -79 dBm
> ModemManager[104]: <debug> Signal strength: -79 dBm --> 55%
> ModemManager[104]: <debug> Modem /org/freedesktop/ModemManager1/Modem/1: access technology changed (unknown -> umts)
> ModemManager[104]: <debug> Modem /org/freedesktop/ModemManager1/Modem/1: signal quality updated (55)
> ModemManager[104]: <debug> Periodic signal quality checks scheduled in 30s
> ModemManager[104]: <debug> Running registration checks (CS: 'yes', PS: 'yes', EPS: 'yes')
> ModemManager[104]: [/dev/cdc-wdm0] sent message...#012<<<<<< RAW:#012<<<<<<   length = 13#012<<<<<<   data   = 01:0C:00:00:03:03:00:1B:00:24:00:00:00
>  ModemManager[104]: [/dev/cdc-wdm0] sent generic request (translated)...#012<<<<<< QMUX:#012<<<<<<   length  = 12#012<<<<<<   flags   = 0x00#012<<<<<<   service = "nas"#012<<<<<<   client  = 3#012<<<<<< QMI:#012<<<<<<   flags       = "none"#012<<<<<<   transaction = 27#012<<<<<<   tlv_length  = 0#012<<<<<<   message     = "Get Serving System" (0x0024)
> ModemManager[104]: <debug> building consolidated registration state: cs 'idle', ps 'unknown', eps 'unknown' --> 'idle'
> ModemManager[104]: <info>  Modem /org/freedesktop/ModemManager1/Modem/0: 3GPP Registration state changed (unknown -> idle)
> ModemManager[104]: <debug> building consolidated registration state: cs 'idle', ps 'idle', eps 'unknown' --> 'idle'
> ModemManager[104]: <debug> building consolidated registration state: cs 'idle', ps 'idle', eps 'idle' --> 'idle'
>
> dbus[1073]: [system] Rejected send message, 2 matched rules; type="method_return", sender=":1.140" (uid=0 pid=104 comm="/usr/sbin/ModemManager  ") interface="(unset)" member="(unset)" error name="(unset)" requested_reply="0" destination=":1.142" (uid=0 pid=240 comm="/usr/bin/ApplnManagerd  ")
>
> After this :
> No logs but  the ModemManager restarts, in fact there is a crash and the core is dumped.
> The ModemManager does restart after that and recovers.
>

Ok, so my assumption was right I think. This is just the daemon
crashing and restarted afterwards by systemd, and in between some MM
client (likely NetworkManager) asked DBus to initiate it, but DBus
activation isn't enabled for MM.

> Also this happens after the ModemReset in all cases.
>

I would suggest to upgrade your ModemManager. 1.10.8 is not even the
latest release in the 1.10.x series.
This PPA has a much newer MM version for Ubuntu 16.04:
https://launchpad.net/~aleksander-m/+archive/ubuntu/modemmanager-xenial

-- 
Aleksander
https://aleksander.es