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

Fri Jun 30 08:00:34 UTC 2017

On 29/06/17 19:20, Eric Caruso wrote:
> 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.
> 

A full reprobe is a bit overkill, yes, but right now that's the only way to not only force the modem in Failed state but also make sure all feature interfaces get un-exported from DBus. A modem in failed state should only allow very few of the feature interfaces exposed, mainly those which would allow to get away from a failed state, like e.g. the Firmware interface.

I'd suggest we keep the full reprobe for now, but also investigate the possibility of getting in the Failed state with the limited interfaces, as that would be much quicker.

>>
>> 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.
> 

I sure hope we're not reprobing completely on SIM unlock notifications... Carlo, could you confirm that?

>>
>> 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.
> 

Ok, thanks.

-- 
Aleksander
https://aleksander.es