Modem SIMCom SIM7600 failed

[Aleksander Morgado]

Hey,

>
> Using ModemManager (version 1.10.8) with modem SIMCom SIM7600G, it
> failed to probe it at boot time.
> If I stop ModemManager and wait a while and then restart it probes it
> better.
> With newest modem firmware it is ok. But I wonder why ModemManager do
> not re-probe it and it failed ?
>

Looks like the device was not able to reply to any QMI message during
the first initial 20s after bootup:
Jan 16 11:19:15 ws-box-v1.1 ModemManager[176]: <debug>
(usbmisc/cdc-wdm0) error checking QMI support: 'Transaction timed out'

I guess we could still update this value even more so that the probing
attempts end up taking longer.

Is this issue happening consistently? Or did it happen randomly?

Would you be able to update the timeout to a value greater than 20s,
e.g. 30s, and see if that solves the problem? The change would be
equivalent to this one:
https://gitlab.freedesktop.org/mobile-broadband/ModemManager/commit/a73b13b67cd1987431f92ea6a4ccc2cb85c51cc7

-- 
Aleksander
https://aleksander.es