SIM hot swap

[Dan Williams]

On Fri, 2014-02-28 at 10:19 +0100, Aleksander Morgado wrote:
> On Fri, Feb 28, 2014 at 10:07 AM, Ben Chan <benchan at chromium.org> wrote:
> > I've been looking into the feasibility of supporting SIM hot swap on a MBIM
> > modem.
> >
> > If ModemManager observes MBIM_CID_SUBSCRIBER_READY_STATUS notifications, it
> > should be able to detect when the SIM is removed, and then put the modem in
> > the disabled state. If ModemManager continues to monitor
> > MBIM_CID_SUBSCRIBER_READY_STATUS notifications, it should be able to detect
> > when the SIM is re-inserted. ModemManager will need to recheck if the SIM is
> > PIN locked when it tries to re-enable the modem. Does it make sense?
> >
> > I guess handling the re-insertion of SIM may not be straightforward due to
> > the way that ModemManager currently handles PIN unlock (during
> > initialization and not enabling) and monitors unsolicited events (only when
> > the 3GPP interface is enabled). It may still be useful to handle the SIM
> > removal.
> 
> 
> I also have some modems that support this feature, at least the
> SierraWireless/Wavecom FXT009 fully allows it. When the SIM is
> removed, though, we need to move the modem to "Failed" state, not to
> "Disabled". The "Failed" state is a state in which we only export the
> basic Modem interface (well, and the Firmware one). We can allow
> plugins to provide methods to be run during this Failed state, e.g. to
> setup unsolicited notification handlers and the like. I don't see any
> problem in adding per-plugin logic to handle the Failed state case,
> but handling the modem fallback to that state when the SIM is removed
> may be problematic. Anyway, yeah, fully agree that we can implement
> this feature.

Me too, we can and should support this.

Dan