I am working with Ubuntu 14.04 LTS, where I would like to connect a Cinterion modem through a serial port - ttyS0 in this case -.
The modem works correctly when the following command is issued:
pppd call OPERATOR
Obtaining some traces in /var/log/syslog similar to these ones:
NetworkManager[911]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
NetworkManager[911]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
NetworkManager[911]: <warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring...
After following this AskUbuntu link I have added a rule for udev, in order to allow ttyS0 to be enabled as a "serial network device":
SUBSYSTEM=="pnp", ACTION=="add", KERNEL=="00:08", ENV{ID_MM_PLATFORM_DRIVER_PROBE}="1"
Due to these outputs:
# udevadm info /dev/ttyS0
P: /devices/pnp0/00:08/tty/ttyS0
N: ttyS0
E: DEVNAME=/dev/ttyS0
E: DEVPATH=/devices/pnp0/00:08/tty/ttyS0
E: ID_MM_CANDIDATE=1
E: MAJOR=4
E: MINOR=64
E: SUBSYSTEM=tty
E: USEC_INITIALIZED=87154
# udevadm info /sys/devices/pnp0/00\:08
P: /devices/pnp0/00:08
E: DEVPATH=/devices/pnp0/00:08
E: DRIVER=serial
E: ID_MM_PLATFORM_DRIVER_PROBE=1
E: SUBSYSTEM=pnp
E: USEC_INITIALIZED=87046
Furthermore, as I wanted to test the debug output of ModemManager I stopeed network manager service. Then, in the output I obtained traces like these ones:
#ModemManager --debug
[...]
ModemManager[3170]: <debug> [1473157920.412477] [mm-device.c:298] mm_device_grab_port(): (/sys/devices/pnp0/00:08) could not get vendor/product ID
ModemManager[3170]: <debug> [1473157920.412643] [mm-plugin-manager.c:576] build_plugins_list(): (Plugin Manager) [ttyS0] Found '5' plugins to try...
ModemManager[3170]: <debug> [1473157920.412662] [mm-plugin-manager.c:580] build_plugins_list(): (Plugin Manager) [ttyS0] Will try with plugin 'Cinterion'
ModemManager[3170]: <debug> [1473157929.569356] [mm-port-probe-at.c:43] mm_port_probe_response_processor_is_at(): Parsing AT got: 'Serial command timed out'
ModemManager[3170]: <debug> [1473157929.569369] [mm-port-probe.c:161] mm_port_probe_set_result_at(): (tty/ttyS0) port is not AT-capable
[...]
ModemManager[3170]: <debug> [1473157935.569494] [mm-plugin-manager.c:417] plugin_supports_port_ready(): (Plugin Manager) (Generic) [ttyS0] found best plugin for port
ModemManager[3170]: <debug> [1473157935.569507] [mm-plugin-manager.c:285] port_probe_context_finished(): (Plugin Manager) 'ttyS0' port probe finished, last one in device
ModemManager[3170]: <debug> [1473157935.569514] [mm-plugin-manager.c:107] find_device_support_context_complete_and_free(): (Plugin Manager) [/sys/devices/pnp0/00:08] device support check finished in '15.157042' seconds
ModemManager[3170]: <info> [1473157935.569638] [mm-device.c:486] mm_device_create_modem(): Creating modem with plugin 'Generic' and '1' ports
ModemManager[3170]: <warn> [1473157935.569779] [mm-plugin.c:900] mm_plugin_create_modem(): Could not grab port (tty/ttyS0): 'Cannot add port 'tty/ttyS0', unhandled serial type'
ModemManager[3170]: <debug> [1473157935.569805] [mm-base-modem.c:1556] finalize(): Modem (Generic) '/sys/devices/pnp0/00:08' completely disposed
ModemManager[3170]: <warn> [1473157935.569816] [mm-manager.c:145] find_device_support_ready(): Couldn't create modem for device at '/sys/devices/pnp0/00:08': Failed to find primary AT port
[...]
So, the process ended with an error and did not found a modem in pnp0/00:08.
What additional steps are supposed to be done?
