Re: Re-activating a context.

[Denis Kenzior <denkenz@gmail.com>]

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Hi Christopher,

<snip>

> I now know why I receive '+CGEV: ME DEACT IP, , 1\r\n'.
> According to Telit support this happens because the context does not get deactivated
> and ofono is trying to request a new IP address although the previous one is still valid.
>
> After the antenna gets disconnected, the modem sends '+CREG: 2' and '+CGREG: 2'.
> In consequence drivers/atmodem/gprs-context.c:telit_gprs_detach_shutdown() is called to end ppp connection and
> 'AT+CGATT=0' is sent.
> 'AT+CGATT=0' should normally deactivate all active contexts, but it returns '+CME ERROR: 30'.

That sounds like a firmware bug, we should be able to tell the modem to 
abort the attach procedure or detach at any time.

> When I try to deactivate the context with +CGACT like ifx does in
> drivers/ifxmodem/gprs-context.c:ifx_gprs_deactivate_primary(), then I get '+CME ERROR: 0' (phone failure).
>

Does sending 'AT+CGACT=0' per 3GPP 27.007 10.1.10 work?

> Furthermore I thought that when I receive 'NO CARRIER' at least then all context should be deactivated.
>  From a Cinterion manual (as the Telit manual is very poor):
> "If the TE wants to close the LCP link the MT may perform an LCP termination request procedure on PPP level.
> After this LCP termination procedure the MT deactivates the PDP context automatically and the MT returns to
> V.250 command mode and issues the final result code NO CARRIER."

Yes, that is the expected behavior, NO CARRIER means context is 
deactivated.  We've had problems with Huawei modems that try to keep the 
PPP link alive when network registration is lost.  We then had to 
force-deactivate them by sending the relevant LCP close procedure.  But 
that doesn't seem to be the issue here...

>
> I don't know if this is a firmware or ofono issue as I don't know how this should be handled correctly.
>

Sounds like firmware is at fault, or maybe the Telit modem has to be 
driven 'differently', but I do not see how.

Regards,
-Denis