SIM PIN unlock timeout

[Dan Williams]

On Wed, 2024-12-11 at 09:59 +0100, Robert Marko wrote:
> On Wed, Dec 11, 2024 at 9:45 AM Aleksander Morgado
> <aleksandermj at chromium.org> wrote:
> > 
> > Hey Dominik,
> > 
> > > 
> > > I am currently trying to unlock my Quectel RM520N-GL on Linux
> > > Debian with the ModemManager (Version 1.20.4).
> > > 
> > > 
> > > 
> > > mmcli -i any --pin=<SIMPIN>
> > > 
> > > > > error: couldn't send PIN code to the SIM: 'Timeout was
> > > > > reached'
> > > 
> > > 
> > > 
> > > Runs into a timeout and still manages to unlock the SIM-Card.
> > > Afterwards the state changes from “locked” to “registered”.
> 
> Hi, I think you are hitting the same issue as I am:
> https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/919


Looking at that log, I think the issue there is that before the SIM is
unlocked MM cannot read the IMSI.

Then when the SIM is unlocked that triggers the Quectel plugin SIM
hotswap logic due to the AT+QUSIM URC. That causes MM to re-read the
ICCID and IMSI to figure out if the SIM has been swapped.

Since the SIM is unlocked now MM can read the IMSI which is a change
from before. That causes the hotswap logic to trigger, which tears down
the modem and recreates it. That cancels running operations like the
SIM PIN entry because of how teardown works.

Perhaps MM should be more selective in how it decides the SIM has been
swapped. For example, if the modem is in the "locked" state and the
IMSI changes from NULL -> [something valid] but the ICCID hasn't
changed, we probably didn't have a SIM swap.

But that might not cover cases like ejecting the SIM, changing the IMSI
in a SIM programmer, and re-inserting. Or OTA reprogramming. Not sure
if that's a valid use-case or not.

Aleksander, any thoughts here?

Dan

> 
> Regards,
> Robert
> > > 
> > > 
> > 
> > 
> > Please run MM with debug logs (use "mmcli -G DEBUG" or follow
> > https://modemmanager.org/docs/modemmanager/debugging/), as that
> > will give us much more information about the specific sequence in
> > place here.
> > 
> > --
> > Aleksander
> 
> 
>