Re: [PATCH 1/1] telit: stay 'online' until POST_SIM state reached

[Denis Kenzior <denkenz@gmail.com>]

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Hi Jonas,

On 12/07/2012 12:22 AM, Jonas Bonn wrote:
> Hi Denis,
>
> On Tue, 2012-12-04 at 23:55 -0600, Denis Kenzior wrote:
>> Hi Jonas,
>>
>> On 12/04/2012 09:46 AM, Jonas Bonn wrote:
>>> In offline state where CFUN=4, the Telit HE910 also powers down the SIM
>>> card so AT commands that query the SIM will fail.  These failures result
>>> in ofono not getting to POST_SIM state where it will export the GPRS
>>> feature.
>
>>
>> Does the HE910 have a proper CFUN mode where it does not turn off the
>> SIM?  You are making some nasty hacks because of it, and the other Telit
>> devices support this just fine.
>
> No, the HE910 supports CFUN modes 0,1,4,5,7 where:
> 1: online
> 4: offline (airplane) mode with SIM powered off
> 0,5,7: online w/ power saving modes; SMS and phone calls are active in
> these modes, but AT command handling seems to be turned off
>
> See Telit Modules Software User Guide, 1vv0300784 rev 11, 2012-09-20,
> section 3.6 (page 105) for a description of these modes.
>

I read the description of CFUN in that document and got lost rather 
quickly.  The bottom line is that oFono does not use any serial 
signaling, so all of these DTR and RTS conditions do not apply.  If the 
Telit modems do not support radio off with SIM on, then you need to 
structure the driver differently, most likely removing the 'online' 
method implementation would do what you want, and use only 
enable/disable.  In theory that should work putting the modem online as 
soon as the sim is in the ready state.

Better yet, ask Telit to fix their firmware and document what the <rst> 
parameter to CFUN actually means.

>>
>>>
>>> This patch changes the Telit driver so it will not go immediately
>>> to CFUN=4 after enable, but to wait for the post_sim state to be
>>> reached before doing so.  In addition, the HE910 might send QSS: 0
>>> unsolicited reports while in CFUN=4 state... this patch makes it so
>>> that these are ignored until the modem is onlined and the actual
>>> SIM state can be queried again.
>>
>> Also remember the modem can be 'Online' even without a SIM, or in
>> pre-SIM state for e.g. emergency calls.  So much of the logic might break.
>
> OK, I need to check what CFUN mode we need in order to be able to make
> emergency calls.  I think 4 won't work... CFUN=4 is really 'airplane
> mode' with antennas off.
>
> My interpretation of modem 'enabled' in ofono is that it's 'airplane
> mode'... is this not correct?
>

It follows the 'Powered' property meaning.  E.g. 'is this thing on?' 
Most regular modem devices enter airplane mode when the driver enabled() 
function is called.  However, that is not the case everywhere.

Regards,
-Denis