Extending OpenWRt ModemManager protocol handler

[Aleksander Morgado]

Hey,

> >>> So here I am at my second attempt to build a solution to enable multi-modems and
> >>> multi-bearers usage in OpenWRt, with re-connection handling for persistent
> >>> connectivity.
> >>>
> >>
> >> This doesn't do anything about multiple modems, but here's my patch for
> >> retry.  Without this, in some instances, ModemManager/netifd will simply
> >> give up and you'll be left with a stopped state.
> >>
> >
> > Please note that patch you're suggesting is reworking the modem
> > detection, nothing to do with the actual connectivity. The missing
> > netifd integration still applies.
> > Regarding that patch; is 45s not enough in your case? If so, the
> > solution would be to increase the timeout, not sure about adding an
> > extra loop for that.
>
> The timeout doesn't matter. Whatever you set it to, it will always be at
> some point "not long enough".

That's not really true, because that timeout is bound to the max time
required by ModemManager to probe the AT/QMI/MBIM ports, which I
believe is close to those 45s max per port (in parallel). Having an
infinite loop there doesn't help, as that max time required by MM is
not arbitrary, that's why I suggested incresing the timeout value;
maybe some of the ports take up to 45s to probe and we just need a
longer timeout when detecting the modem in DBus.

-- 
Aleksander
https://aleksander.es