Upgrade to ModemManager fsils

[Aleksander Morgado]

Hey Karsten!

> We have upgraded some of our units from a old version of openwrt  to a new openwrt version with ModemManager.
> Several of the update works OK. But other update fails. The main symptom is modem manager do not connect
> Reboot of CPU which run openwrt do not change anything.  Nor reboot the Quectell modem change the situation
>
> New SW versions are
>      OpenWrt 19.07.2
>      ModemManager daemon 1.14.12
>      mmcli 1.14.12
>
> We have noticed suspicious differences when using the mmcli -m xx cmd on unit which work OK contra on unit which fail after upgrade.Remark the missing parameters on fail unit
> The suspicious differences are:
>  group    parameter                  value on fail unit              value on OK unit
> -----------------------------------------------------------------------------------------------------
> Hardware  carrier config             Commercial-TMO_VoLTE            ROW_Generic_3GPP
> System    drivers                    option, qmi_wwan                qmi_wwan, option

I don't have a clear explanation as to why in one case no SIM is
detected, while it is in the other case, but this carrier config
difference you point out here is a very important one.
My suggestion would be to try to install the generic 3GPP carrier
config in the modem that reported the missing SIM, and see what
happens. You should definitely contact Quectel to try to see if they
can spot what the reason could be. Also, try to ask the question in
the Quectel forum if your Quectel contact doesn't give you a good
answer: https://forums.quectel.com/c/iot-module/lte-standard-module/33

Another thing. In order to make sure it is not a timing issue, if you
boot the system and restart ModemManager after some minutes, is the
SIM still reported as missing?

-- 
Aleksander