libqmi instead of NetworkManager?

[Aleksander Morgado]

On Fri, Oct 2, 2015 at 4:34 PM, Paul R <r_paulr at outlook.es> wrote:
>>
>> The thing is that the MC7354 is both GSM/UMTS/LTE and CDMA/EVDO, so
>> ModemManager tries to match CDMA/LTE related rules as well as the
>> GSM/UMTS/LTE ones. When using libqmi/qmicli directly you can just
>> ignore all CDMA related stuff. When using ModemManager, the modem
>> should still allow you to connect to GSM/UMTS/LTE even if CDMA/EVDO is
>> not available; if it doesn't let you connect, that would be a problem.
>>
>
> Yes, it lets me connect.So then the "lag time" problem is has nothing to do
> with CDMA.
> Anyway, I´d like to disable that CDMA probes. Is possible to use qmicli to
> do that?
>

You could try to tell the modem it shouldn't report CDMA with qmicli:

qmicli -d /dev/cdc-wdm0 --nas-set-system-selection-preference='gsm|umts|lte'

BUT ModemManager may anyway use other means to know if the modem
supports CDMA. There really are no CDMA "probes" anyway, we check
registration status for both GSM/UMTS/LTE and CDMA/EVDO, and if the
modem supports CDMA we also report about the CDMA status, in addition
to the GSM/UMTS/LTE status.


> Regarding the "Gobi/Sierra" plugin issue in my previous post...
> Do you thing the plugin ModemManager is using should be Sierra or Gobi ?
> (In logs, it says "Gobi" and "generic" )
>

In the next release, I'm trying to make all Sierra QMI modems handled
by the Sierra plugin, so that we can subclass modem implementations
per vendor. In your version, it is ok if it's handled by the Gobi
plugin; that is just because the Gobi plugin matches by driver earlier
than the Sierra plugin by vendor ID, but both QMI implementations will
be the same.

> I´m waiting for some MomemManager logs with --debug from my embarked system.
> We know sometimes there are radio cell handovers and some places were signal
> strength/quality is not as good as in others.
> Perhaps this modem is too slow detecting an stable condition and waits too
> much before informing upper layers all is ok.
> If so, how could I use qmicli (or my own binary linked with libqmi) to check
> that condition?
>

If you want to use qmicli or a program+libqmi, you'd need to run your
own WDS client to get the modem in connected mode, and then check the
"packet service status" to see if it got disconnected or not, so that
you can trigger your own connection retries.

-- 
Aleksander
https://aleksander.es