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Created attachment 1494112[details]
journal showing the issue
Situation:
- wwan device with ppp connected (and pppd running)
> Oct 15 20:10:17 Ajohn.pnq.csb pppd[14857]: nm-ppp-plugin: (nm_ip_up): ip-up event
- ModemManager exits
> Oct 15 20:10:39 Ajohn.pnq.csb systemd[1]: Stopping Modem Manager...
...
> Oct 15 20:10:59 Ajohn.pnq.csb ModemManager[4928]: <warn> Disabling modems took too long, shutting down with '1' modems around
- NetworkManager notices the modem is gone and sets the device state to disconnected
> Oct 15 20:10:59 Ajohn.pnq.csb NetworkManager[1166]: <info> [1539614459.1484] modem-manager: ModemManager no longer available
> Oct 15 20:10:59 Ajohn.pnq.csb NetworkManager[1166]: <debug> [1539614459.1489] manager: (ttyUSB2): removing device (allow_unmanage 1, managed 1)
> Oct 15 20:10:59 Ajohn.pnq.csb NetworkManager[1166]: <trace> [1539614459.1490] device[0x562822c13a70] (ttyUSB2): sys-iface-state: managed -> removed
- it seems, it can happen that pppd daemon is left running
(note: process 14857 is running until much later at
> Oct 15 20:18:47 Ajohn.pnq.csb pppd[14857]: rcvd [LCP TermReq id=0x19]
> Oct 15 20:18:47 Ajohn.pnq.csb pppd[14857]: LCP terminated by peer
- upon restart, ModemManager cannot access the modem
> Oct 15 20:10:59 Ajohn.pnq.csb systemd[1]: Started Modem Manager.
...
> Oct 15 20:11:16 Ajohn.pnq.csb ModemManager[16433]: <warn> Couldn't create modem for device at '/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2': Failed to find pri
Also: see (probably related) assertion:
Oct 15 20:18:50 Ajohn.pnq.csb NetworkManager[1166]: g_signal_emit_valist: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
Versions:
rhel-7.5 Kernel: 3.10.0-862.6.3.el7.rh1630402.1.90.x86_64
(which is identical to "3.10.0-862.6.3.el7" + patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19445816996d1a89682c37685fe95959631d9f32
NM version: 1.10.2-16.el7_5
I've tested this extensively and I'm unable to reproduce this particular problem (though encountered some different problems).
It could very well be that this has been fixed upstream.