GPRS support for Ofono

[Denis Kenzior]

Hi Remi,

> On Sat, 05 Dec 2009 17:37:36 +0100, Marcel Holtmann <marcel at holtmann.org>
>
> wrote:
> > since we have the upstream GPRS support for MBM and HSO devices, it
> > would be great to have this for Phonet, too. I tried to work on the
> > patch, but without proper documentation it is impossible. So please
> > adapt it to the current upstream and resend it.
>
> I can't quite implement the current API for ISI modem. For a start, ofono
> is currently crashing in setpowered as soon as it sees an ISI modem.

Wasn't this fixed by commit ee1e9d14bde006da64d3e9d0c1f61523f113869a?

If not, get me a backtrace or a patch.

>
> But there are some more fundamental issues. First, the ISI General Packet
> Data Service does not provide any location informations (roaming/not
> roaming, area code, cell ID). And I must say I don't understand why this is
> part of the GPRS atom. This has nothing to do with packet data.

That is because 3GPP in their infinite wisdom structured the spec this way.  
There are 2 registration states, one reported by CREG and one reported by 
CGREG.  Both report essentially the same information, namely registration 
status, lac, cellid and radio access technology.

The way we know an AT-command based modem is attached is when we start 
receiving these CGREG indications (registered/roaming + lac/ci/rat)

I'm open to suggestions on how to fix this (for instance we can get rid of 
Status, LocationAreaCode, CellId attributes, since they're essentially the 
same as in NetworkRegistration interface), but for now this can be easily 
faked by just re-using the information you're providing to netreg atom.

>
> Second, I couldn't figure how to handle auto-attach. The ISI protocol
> supports it, but I could not find the driver callback. Thus, I would have
> to force the device into manual mode. This is going to be an issue as some
> operators require auto-attach

Is this where the network requests an attach or are you talking about 
something else?

Regards,
-Denis