unable to reconnect to "MM_MODEM_STATE_REGISTERED" status modem until it's reset

[Héctor Jiménez Méndez]

Thank you!

We'll consider updating MM to newer versions depending on how our workaround affects the user experience.

Kind regards!


Héctor Jiménez Méndez
Firmware engineer

T. 983 54 65 54
M. 696 297 286

Juan de Herrera, nº 17, P.T.B.
47151 Boecillo, Valladolid | Spain







www.gmv.com


-----Mensaje original-----
De: Aleksander Morgado <aleksandermj at chromium.org> 
Enviado el: domingo, 25 de junio de 2023 0:31
Para: Héctor Jiménez Méndez <hector.jimenez.m at gmv.com>
CC: modemmanager-devel at lists.freedesktop.org
Asunto: Re: unable to reconnect to "MM_MODEM_STATE_REGISTERED" status modem until it's reset

Hey,

>
> We are using ModemManager 1.12.12 library in one of our projects and we are getting MM_MODEM_STATE_REGISTERED status when polling for Modem status with mm_modem_get_state function.
>
>
>
> Then we try to connect again by using mm_modem_simple_connect_sync 
> function to get the bearer, and then mm_bearer_connect_sync with that 
> bearer, which gets all bearer parameters,
>
>
>
> But modem still in MM_MODEM_STATE_REGISTERED status after that.
>
>
>
> Then we try again and finally restart the modem device and finally achieve to reconnect to modem.
>
>
>
> In some other situations, this procedure reconnects at first try, but we don’t know why exactly modem returns MM_MODEM_STATE_REGISTERED status itself.
>
>
>
> Our system in boarded on a vehicle which is in moving around, so we are thinking it could be a matter of signal loss, but mmcli tool doesn’t show low signal values. It shows modem in “registered” stated though when this happens.
>
>
>
> We are able to reconnect by “simple disconnect” the modem when it gets in “registered” state and before doing the reconnection procedure described above, but I seriously doubt this is the correct way to handle it.
>
>
>
> Is there any known/solved issue about this “registered” modem state relating to this version of the library?
>
>
>
> If not… any ideas about properly handling it?
>

This vaguely reminds me to some issue years ago, but my memory is not that good. MM 1.12 is extremely old and we have fixed and improved the whole stack a lot in the next releases.

--
Aleksander

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