forbid Roaming

[Dan Williams]

On Wed, 2013-01-09 at 16:27 +0100, A. Valentin wrote:
> Hi Aleksander
> 
> Am 09.01.2013 16:15, schrieb Aleksander Morgado:
> > What happens if you force it to re-register? Maybe it just doesn't
> > honour the new request until you re-register. 
> 
> Even if I switch the device off, the roaming flag is still set. Seems to
> be permanently stored. And it registers.....

It's probably the same internally as the QCDM "RoamPref" NV item, which
may only be relevant for CDMA devices.  In which case it may be
available to set, but simply ignored for 3GPP devices, since roaming
isn't handled the same way there.

> Another idea is to only allow manual network selection if roaming is
> disabled in frontend.
> Perhaps that's the best workaround...

Forcing manual network selection can break in-network roaming when your
operator uses multiple MCC/MNCs, which occurs often in the USA and
India.  Manual selection isn't a great fix for this.

I think instead that the modem manager should be handling roaming
control, instead of trying to hack around this at the firmware level.
For most cases, CREG or the QMI "roaming indicator" will show the
correct roaming state (determined though various SIM filesystem tables
and network information) which the connection manager can use to
terminate the connection if the user has elected to disable roaming.

In short: don't expect libqmi to be a connection manager, that's not
what it's for.  It speaks QMI only, and leaves the actual interesting
logic to something like ModemManager.

Dan