[Gta04-owner] Polling CLCC error handling on Option modem (GTA04)

[Dr. H. Nikolaus Schaller]

Am 05.03.2012 um 20:26 schrieb Denis Kenzior:

> Hi Radek,
> 
> On 03/06/2012 02:47 PM, Radek Polak wrote:
>> Hi,
>> first of all QtMoko [1] now supports ofono as another telephony backend [2]. We 
>> have also autogenerated qt bindings [3] which can be interesting also for 
>> other projects.
>> 
> 
> Nice.
> 
>> But now the problem that has already been discussed. If you make call to GTA04 
>> with ofono running, it starts CLCC polling. After you hangup sometimes 
>> everything is ok and the call disappears:
>> 
>> fonod[1027]: App: < \r\n+CLCC: 1,1,4,0,0,"+420608828973",145\r\n\r\nOK\r\n
>> ofonod[1027]: App: > AT+CLCC\r
>> ofonod[1027]: App: < \r\nOK\r\n
>> ofonod[1027]: src/voicecall.c:ofono_voicecall_disconnected() Got disconnection 
>> event for id: 1, reason: 2
>> ofonod[1027]: App: < \r\n_OSIGQ: 18,0\r\n
>> ofonod[1027]: src/network.c:ofono_netreg_strength_notify() strength 58
>> ofonod[1027]: App: > AT+CLCC\r
>> ofonod[1027]: App: < \r\nOK\r\n
>> 
>> but sometimes the modem returns error:
>> 
>> ofonod[1027]: App: < \r\n+CLCC: 1,1,4,0,0,"+420608828973",145\r\n\r\nOK\r\n
>> ofonod[1027]: App: > AT+CLCC\r
>> ofonod[1027]: App: < \r\n+CME ERROR: 100\r\n
>> ofonod[1027]: We are polling CLCC and received an error
>> ofonod[1027]: All bets are off for call management
>> 
>> and ofono never reports that the call is removed. The result is that GUI shows 
>> dialed call forever.
>> 
>> I know that modem should not return error, but it would be nice to have at 
>> least some workaround. E.g. assume remote hangup or missed call.
> 
> My standard reply for such modems is to talk to your vendor and demand
> the firmware to be fixed.  If this isn't possible, then please perform

If you are in a good position to demand something. If you buy 100k modems
per year you certainly can :)

We have asked, and besides that getting responses is slow, the answer was
to upgrade the firmware. But it is not yet understood how that works and if
it can be done easily and which other problems arise. We only know that
a downgrade to go back to the current one is not possible.

> these steps:
> 	window.open();
> 	window.throw(modem);

s/modem/ofono/? -- just joking :)

> 	window.close();
> 
> :)
> 
> It seriously might be easier to get another modem than trying to work
> around such nasty bugs in the modem firmware.  You will never be able to

Do you know how much time and work it did take to find a modem that fits
into the space constraints, and can still be bought in small quantities?

And how much work and money it is to define a PCB layout and have
the soldering process set up so that there are no short circuits or bad
connections?

This means replacing the modem is not a realistic option in the next months :(

> hit any sort of power consumption targets with CLCC polling anyway.
> Such behavior from the modem firmware is not acceptable, even the old
> Calypso modem in the Freerunner was better here.

But it was worse in approx. 80% of the other features. So why throw away
80% if this is the first bug we find?

> 
>> 
>> Or anyone has better ideas?
>> 
> 
> You can always try ignoring CME ERROR 100 and re-try the CLCC poll.
> Maybe the modem is in a transitional period (e.g. call being released)
> and it can't answer the CLCC properly.  In other words, there's a bug
> related to timing of call state changes & CLCC implementation in the
> modem firmware.

This is what I also think that happens...

> 
> Regards,
> -Denis

BR,
Nikolaus