Modem interface initialization

[Aleksander Morgado]

Hey Alexey,


>
> A few Qualcomm based modems require a reboot after some configuration
> settings were changed and saved in NVM.
> It makes sense to set such a parameter during initialization and
> reboot modem right away by using modem interface reset() or by
> AT command directly. Would such an approach lead to any MM issues?
>

In general, what I always suggest is that if you're changing settings
in the modem that may affect how ModemManager manages the device, then
you should change those settings only if ModemManager is not using the
device. An example on how to do this is the "inhibition" interface;
you can inhibit a modem, MM will get rid of all control it had over
it, and then you can do whatever you want with the device. Only once
the inhibition is removed, MM will try to talk to the device again.

A different approach would be to have the modem configuration change
done on boot and synchronize it so that MM doesn't start until the
configuration changes have been made.

And the last approach I can think of is to apply the changes during
runtime even if ModemManager is using the modem, but run a full device
reboot after the changes. Doing this is quite safe because once the
modem boots, MM will take full control over it and no more config
changes are expected.

-- 
Aleksander