Re: [MM] [PATCH] sim: retry SIM operations during initialization

[Aleksander Morgado <aleksander lanedo com>]

>> Do you mean that you still need the timeout even if the PIN request is
>> not enabled?
>>
>> If the code tries to load Sim properties before unlocking the PIN and
>> those fail, they will anyway get retried after the successful PIN unlock.
> 
> Yes, the issue happens on a SIM without PIN locked. One scenario is
> when the modem is powered off during suspend. After the system
> resumes, the modem boots up and ModemManager sees a new device.
> ModemManager gets a CPIN response from the modem indicating that no
> PIN unlock is required. If ModemManager immediately issues AT+CRSM to
> access ICCID or IMSI, the command either fails with a +CRSM,110,0
> response or sometimes a bogus value (which could be a problem with the
> modem firmware, but we somehow need to work around that in software).
> It becomes more reliable if there is a delay between getting CPIN
> ready and initializing MMSim.  Similar problem could happen on a
> system that finishes booting (and launching ModemManager) before the
> SIM interface is fully ready.
> 

I see; so yes, we should probably run the after-sim-unlock waiting step
also after getting the READY reply without having inserted the PIN
ourselves.

Then, the after-sim-unlock step may be implemented either as:
 * just sleeping for some ms; like the MBM plugin does.
 * or issuing a command known to need access to the SIM (e.g. +CPMS?);
like the ZTE plugin does,
 * or any other method to (try to) ensure the SIM is ready.

I'll look into moving the after-sim-unlock step.

-- 
Aleksander