Have you tried if the same happens with modemmanager?
No, i haven`t. And it's not really relevant for me, as modemmanager
might match interfaces in a different way.
It looked weird to me to have a single parent interface for both the
cdc_dwm device and the wwan device, while there are separate
usb_interfaces for control and data.
From Bjørn's explanation, i understand why this was done. And i will
take a look at how this can be changed in ofono.
Thanks,
Cedric