[PATCH] mm-broadband-modem-mbim: support hot swapping

Thu Jun 29 17:20:59 UTC 2017

Thanks for taking a look at this!

On Thu, Jun 29, 2017 at 3:22 AM, Carlo Lobrano <c.lobrano at gmail.com> wrote:
> Hi,
>
>> If I'm not mistaken, whenever a sim insert/removal event is detected, we
>> should just call
>> mm_broadband_modem_update_sim_hot_swap_detected(), which will trigger a
>> full modem re-probe.

I had imagined that a full re-probe on SIM removal was overkill, and
the discussion in thread
https://lists.freedesktop.org/archives/modemmanager-devel/2014-February/000914.html
seemed to land on moving the modem into the failed state rather than
disabling it. I suppose the re-probe will re-initialize it and it will
get to the failed state because it doesn't have a SIM inserted, so I
can change this if that's what we want.

>
> yes, I confirm this. mm_broadband_modem_update_sim_hot_swap_detected will
> trigger full re-probe and disable current modem.
>
> Here is the code in telit plugin
>
>
> 133     if ((prev_qss_status == QSS_STATUS_SIM_REMOVED && cur_qss_status !=
> QSS_STATUS_SIM_REMOVED) ||
> 134         (prev_qss_status > QSS_STATUS_SIM_REMOVED && cur_qss_status ==
> QSS_STATUS_SIM_REMOVED)) {
> 135         mm_info ("QSS: SIM swap detected");
> 136         mm_broadband_modem_update_sim_hot_swap_detected
> (MM_BROADBAND_MODEM (self));
> 137     }
> The if condition is a bit complex here because we can have 4 different QSS
> states, but if we are tracing just 2 or them (SIM IN vs SIM OUT), and if I'm
> not wrong here, whenever last_ready_state and ready_state differ,
> mm_broadband_modem_update_sim_hot_swap_detected should be called
>
>     if self->priv->last_ready_state != ready_state:
>         mm_broadband_modem_update_sim_hot_swap_detected (...)
>

If I'm not mistaken, the
basic_connect_notification_subscriber_ready_status callback will
trigger on any change in the subscriber ready state, so this would
catch other state changes such as unlocking the SIM.

>
> On 29 June 2017 at 11:08, Aleksander Morgado <aleksander at aleksander.es>
> wrote:
>>
>> On 29/06/17 10:51, Aleksander Morgado wrote:
>> >> +    if (self->priv->last_ready_state !=
>> >> MBIM_SUBSCRIBER_READY_STATE_SIM_NOT_INSERTED &&
>> >> +        ready_state == MBIM_SUBSCRIBER_READY_STATE_SIM_NOT_INSERTED) {
>> >> +        /* SIM has been removed */
>> >> +        mm_iface_modem_update_failed_state (MM_IFACE_MODEM (self),
>> >> +
>> >> MM_MODEM_STATE_FAILED_REASON_SIM_MISSING);
>> >> +    } else if (self->priv->last_ready_state ==
>> >> MBIM_SUBSCRIBER_READY_STATE_SIM_NOT_INSERTED &&
>> >> +               ready_state !=
>> >> MBIM_SUBSCRIBER_READY_STATE_SIM_NOT_INSERTED) {
>> >> +        /* SIM has been reinserted */
>> >> +        mm_broadband_modem_update_sim_hot_swap_detected
>> >> (MM_BROADBAND_MODEM (self));
>> >> +    }
>> >>
>> > If I'm not mistaken, whenever a sim insert/removal event is detected, we
>> > should just call mm_broadband_modem_update_sim_hot_swap_detected(), which
>> > will trigger a full modem re-probe. In this case the method is only being
>> > called for the case where the SIM is inserted, not for when the SIM is
>> > removed.
>> >
>>
>> Also, could you provide MM debug logs showing the SIM card hot insertion
>> and the SIM card hot removal?

Removal puts this in the logs:

2017-06-29T09:52:09.749860-07:00 INFO ModemManager[7755]: <debug>
Received notification (service 'basic-connect', command
'subscriber-ready-status')
2017-06-29T09:52:09.749918-07:00 INFO ModemManager[7755]: <info> Modem
/org/freedesktop/ModemManager1/Modem/0: state changed (connected ->
failed)
2017-06-29T09:52:09.759901-07:00 INFO ModemManager[7755]: <debug>
Disconnecting bearer '/org/freedesktop/ModemManager1/Bearer/0'
2017-06-29T09:52:09.760052-07:00 INFO ModemManager[7755]: <info> Modem
/org/freedesktop/ModemManager1/Modem/0: state changed (failed ->
disconnecting)
2017-06-29T09:52:09.760772-07:00 INFO ModemManager[7755]: <debug> Not
enabling periodic signal checks: unsupported
2017-06-29T09:52:09.760832-07:00 INFO ModemManager[7755]: <debug>
Launching disconnection on data port (net/wwan0)

and reinsertion puts this in the logs:

2017-06-29T09:54:02.475438-07:00 INFO ModemManager[7755]: <debug>
Received notification (service 'basic-connect', command
'subscriber-ready-status')
2017-06-29T09:54:02.475481-07:00 INFO ModemManager[7755]: <debug>
Releasing SIM hot swap ports context
2017-06-29T09:54:02.475544-07:00 INFO ModemManager[7755]: <debug>
(ttyACM0) device open count is 1 (close)
2017-06-29T09:54:02.475586-07:00 INFO ModemManager[7755]: <debug>
(ttyACM2) device open count is 1 (close)
2017-06-29T09:54:02.475743-07:00 INFO ModemManager[7755]: <info> Modem
/org/freedesktop/ModemManager1/Modem/0: state changed (registered ->
disabling)
2017-06-29T09:54:02.476583-07:00 INFO ModemManager[7755]: <debug>
Modem has time capabilities, disabling the Time interface...
2017-06-29T09:54:02.476704-07:00 INFO ModemManager[7755]: <debug>
Modem has messaging capabilities, disabling the Messaging interface...
...
2017-06-29T09:54:02.506030-07:00 INFO ModemManager[7755]: <info> Modem
/org/freedesktop/ModemManager1/Modem/0: 3GPP Registration state
changed (idle -> unknown)
2017-06-29T09:54:02.506323-07:00 INFO ModemManager[7755]: <debug>
Bearer not allowed to connect, not registered in 3GPP network
...
2017-06-29T09:54:02.515322-07:00 INFO ModemManager[7755]: <info> Modem
/org/freedesktop/ModemManager1/Modem/0: state changed (disabling ->
disabled)
2017-06-29T09:54:02.516099-07:00 INFO ModemManager[7755]: <debug>
Removing from DBus bearer at '/org/freedesktop/ModemManager1/Bearer/0'
2017-06-29T09:54:02.516145-07:00 INFO ModemManager[7755]: <debug>
[device /sys/devices/pci0000:00/0000:00:14.0/usb1/1-1] unexported
modem from path '/org/freedesktop/ModemManager1/Modem/0'
...
2017-06-29T09:54:02.518943-07:00 DEBUG ModemManager[7755]: opening device...
...
2017-06-29T09:54:02.587822-07:00 INFO ModemManager[7755]: <debug>
loaded modem capabilities: gsm-umts, lte
2017-06-29T09:54:02.587842-07:00 INFO ModemManager[7755]: <debug>
Setting EPS network as supported
2017-06-29T09:54:02.588054-07:00 INFO ModemManager[7755]: <debug>
Modem allows up to 1 bearers
2017-06-29T09:54:02.588074-07:00 INFO ModemManager[7755]: <debug>
Creating bearer list (max: 1, max active: 1)

which looks like disabling and reprobing. Most of the elided stuff is
either raw MBIM messages or AT commands. Let me know if you want to
see anything else.

>>
>> --
>> Aleksander
>> https://aleksander.es
>
>