Quectel EC21-A fails with new and freshly activated Twilio SIM card

[Aleksander Morgado]

Hey!

On Thu, May 14, 2020 at 4:36 PM Zahari Petkov <zahari at balena.io> wrote:
>
> Hi,
>
> We are facing an issue with a Quectel EC21-A module and Twilio SIM cards using ModemManager v1.12.8. I found similar error logs with Soracom SIM cards and other Quectel modems as well.
>
> A new and freshly activated Twilio SIM card would not work unless the modem is reset. Rebooting does not make the issue go away. After the modem is reset the SIM card start working. IPv6 is disabled.
>
> The non-verbose logs are:
>
> ```
> May 13 16:54:07 f79fae5 ModemManager[1139]: Simple connect started...
> May 13 16:54:07 f79fae5 ModemManager[1139]: Simple connect state (4/8): Wait to get fully enabled
> May 13 16:54:07 f79fae5 ModemManager[1139]: Simple connect state (5/8): Register
> May 13 16:54:07 f79fae5 ModemManager[1139]: Simple connect state (6/8): Bearer
> May 13 16:54:07 f79fae5 ModemManager[1139]: Simple connect state (7/8): Connect
> May 13 16:54:07 f79fae5 ModemManager[1139]: Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
> May 13 16:54:08 f79fae5 ModemManager[1139]: error: couldn't start network: QMI protocol error (14): 'CallFailed'
> May 13 16:54:08 f79fae5 ModemManager[1139]: call end reason (1): 'generic-unspecified'
> May 13 16:54:08 f79fae5 ModemManager[1139]: verbose call end reason (3,2504): [cm] invalid-sim-state
> May 13 16:54:08 f79fae5 ModemManager[1139]: Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
> ```
>

Interestingly, I recently found one issue exactly like that with a
Quectel EG06-E. I believe I was able to recover the connection putting
the modem in low power mode (mmcli --disable and then mmcli
--set-power-state-low) before trying to reconnect again, but I'm not
completely sure, I didn't take note of what I did or didn't do.... In
my case, though, it didn't happen on a fresh module boot, I think the
setup got in that state after a lot of time being already connected.

I do remember that I tried to debug the problem and gather e.g. QMI
UIM card status info and such, and everything looked correct to me. It
does look like a firmware bug, if you ask me...

-- 
Aleksander
https://aleksander.es