[PATCH v2] telit: lock/unlock CSIM operations by default

[Aleksander Morgado]

On Thu, Mar 16, 2017 at 10:58 AM, Carlo Lobrano <c.lobrano at gmail.com> wrote:
> Sorry for the late reply, but I was double checking this change because of
> the last paragraph in +CSIM reference:
>
>> After the locking of the SIM-ME interface (AT+CSIM=1) the SIM will be
>> accessible only by AT+CSIM commands (#QSS: 0). The GSM and GPRS services
>> will be automatically de-registered to avoid the TE commands alter the GSM
>> application. They will be automatically reconditioned after the unlocking
>> of the
>> SIM-ME interface. After the unlocking of the SIM-ME interface if PIN is
>> required
>> it will be necessary to enter it another time.
>
> But this does not seems to affect the behaviour of the modem, which still
> works fine.
> In my environment I can't reproduce the issue this patch fixes (tty locked),
> but I do not see any side effect, so for me it's ok.
>
>

Good!

> But, while this patch does not cause regression, I did observe a problem
> testing this use case: when SIM is locked and then unlocked, with SIM hot
> swap enabled, we receive an unsolicited "#QSS: 1", which is not related to
> any physical SIM insertion, and release the modem:
>
>
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> (ttyACM0): --> 'AT+CSQ<CR>'
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> (ttyACM0): <-- '<CR><LF>'
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> (ttyACM0): <-- '+CSQ:
> 9,4<CR><LF><CR><LF>OK<CR><LF>'
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> (ttyACM0) device open count
> is 3 (close)
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> Modem
> /org/freedesktop/ModemManager1/Modem/0: signal quality updated (29)
> mar 16 09:55:00 d2092 ModemManager[542]: <debug> Periodic signal quality
> checks rescheduled (interval = 30s)
> mar 16 09:55:02 d2092 ModemManager[542]: <debug> (ttyACM3): <--
> '<CR><LF>+CIEV: service,1<CR><LF>'
> mar 16 09:55:02 d2092 ModemManager[542]: <debug> (ttyACM3): <--
> '<CR><LF>+CIEV: roam,0<CR><LF>'
> mar 16 09:55:05 d2092 ModemManager[542]: <debug> (ttyACM0) device open count
> is 4 (open)
> mar 16 09:55:05 d2092 ModemManager[542]: <debug> (ttyACM0): -->
> 'AT+CCLK?<CR>'
> mar 16 09:55:05 d2092 ModemManager[542]: <debug> (ttyACM0): <-- '<CR><LF>'
> mar 16 09:55:05 d2092 ModemManager[542]: <debug> (ttyACM0): <-- '+CCLK:
> "17/03/16,09:55:05+04"<CR><LF><CR><LF>OK<CR><LF>'
> mar 16 09:55:05 d2092 ModemManager[542]: <debug> (ttyACM0) device open count
> is 3 (close)
> mar 16 09:55:09 d2092 ModemManager[542]: <debug> (ttyACM3): <--
> '<CR><LF>#QSS: 1<CR><LF>'
> mar 16 09:55:09 d2092 ModemManager[542]: <info>  QSS: SIM inserted
> mar 16 09:55:09 d2092 ModemManager[542]: <debug> Releasing SIM hot swap
> ports context
>
> This happens with master ModemManger too.
>
> I'm working on this now, probably a solution would be to borrow Aleksander
> patch about #QSS: 3, in order to keep an internal state of the SIM presence
> and just ignore #QSS: 1 when we already know that SIM is inserted.

Is this extra "#QSS: 1" indication maybe a way the modem has to say
"SIM ready" when it has been configured with "#QSS=1" instead of
#QSS=2? If it happens just after SIM-PIN unlock, it could very well
be.

-- 
Aleksander
https://aleksander.es