Use a specific device ?

[Jean-Christian de Rivaz]

Le 26. 05. 15 16:37, Aleksander Morgado a écrit :
> On Tue, May 26, 2015 at 12:19 AM, Jean-Christian de Rivaz <jc at eclis.ch> wrote:
>> I have a system where the modem have multiple /dev/ttyACMx ports where x is
>> not constant because of the dynamic nature of others serial devices.
>> ModemManager always detect the rights ttyACMx of the modem but
>> NetworkManager only allow to configure a connection for a fixed device. I
>> tried to solve this problem by adding udev rules to fix the device name of
>> the modem, but it's only possible to add a fixed symbolic link. ModemManager
>> seem to ignore the fixed symbolic link and only use the dynamic ttyACMx.
>>
>> Is there a way to force ModemManager to only use a specific symbolic link to
>> control the modem, so that NetworkManger can be configured using a fix
>> device name ?
> There's no current way to do that; instead, the NM settings should be
> bound to either the SIM ICCID (if SIM available) or otherwise to the
> Equipment ID (built from e.g. the IMEI).
>

The proposed idea is to have a udev rule that contain something like 
this ENV(ID_MM_DEVICE_TAG_NAME)="gsm" if the rule match,  then 
ModemManager can use the tag 'gsm' as a fixed reference instead of the 
dynamic ttyACMx. Of course ModemManager will continue to use the dynamic 
ttyACMx internally to communicate with the modem but will use the 'gsm' 
tag on the D-Bus so that NetworkManager get a fixed name too.

Now if you prefer to use the device ID or the SIM ID, ModemManager could 
be configured by a udev rule like ENV(ID_MM_DEVICE_TAG_TYPE)="device-id" 
or "sim-id" for example.

Jean-Christian