Re: [PATCH 1/4] Add: Online property to modem

[Denis Kenzior <denkenz@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 1877 bytes --]

Hi Pekka,

> 2010/5/27 Denis Kenzior <denkenz@gmail.com>:
> > Hi Pekka,
> >
> >> 2010/5/27 Denis Kenzior <denkenz@gmail.com>:
> >> > Patch has been applied, however I did some refactoring afterward.
> >> >  Please test that I didn't break something.
> >>
> >> There is now a race condition in online/offline and sim hotswap. With
> >> imperfect hw a missing sim gets detected only when modem attempts to
> >> register to network and actually tries to read something from sim
> >> card. I have no idea if the missing sim can be reported before +cops
> >> command response is returned.
> >
> > Sorry, but how does such a modem even get to the sim ready state?  oFono
> > reads the IMSI before it even tries to send post_sim, and you certainly
> > can't read the IMSI without a sim card.
> 
> If you have a SIM card and then remove it, modem should go to pre_sim
> state (and the expectation is that it will go offline, too.)  However,
> unless explicitly told otherwise, isimodem goes to limited service
> mode.

Still having trouble seeing your concerns.  oFono core transitions the modem 
to the pre_sim state.  If a modem requires special steps to be taken to be in 
sync with the core, then the driver has to take care of it.

> 
> >> However, at least isimodem needs explicitly told to go offline when
> >> sim gets removed.
> >
> > My thinking is that the modem drivers can take care of this.  The core
> > needs to be kept simple here and assume an 'ideal' implementation.
> >
> > I'm still having trouble understanding how we'll support emergency calls
> > with no SIM with this framework though.
> 
> The online/offline cuts in only if you have SIM card (and PIN is
> entered/disabled).
>

And we rely on the modem to activate rx/tx in the case of an emergency call? 
How does this work with Flight mode?

Regards,
-Denis