Use systemd on-hardware activation
Submitted by Aleksander Morgado
Assigned to ModemManager bug user
Originally reported at: https://bugzilla.gnome.org/show_bug.cgi?id=703039
ModemManager could be configured to be started automatically whenever a possible port to probe is detected in the system. This could be achieved by setting up rules in systemd to launch MM whenever ports with e.g. a special tag (like our ID_MM_CANDIDATE) are found.
ModemManager would still allow DBus activation, though. E.g. if a explicit Scan() is requested via DBus.
In both those cases, MM could exit after some period without any device found to manage.