Portanto, tenho o T470 com o EM7455 instalado e, seja o que for que eu faça, não é possível estabelecer uma conexão. Ele se registra na rede com sucesso, mas quando estou tentando estabelecer uma conexão, aqui está o que eu vejo em journalctl -f :
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.5623] device (cdc-wdm0): Activation: starting connection 'vivacom connection 1' (458a0a50-3b85-4778-ba9d-45d59a990a43)
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.5629] audit: op="connection-activate" uuid="458a0a50-3b85-4778-ba9d-45d59a990a43" name="vivacom connection 1" pid=31543 uid=1000 result="success"
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.5635] device (cdc-wdm0): state change: disconnected -> prepare (reason 'none', internal state 'managed')
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.5657] device (cdc-wdm0): state change: prepare -> need-auth (reason 'none', internal state 'managed')
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.6240] device (cdc-wdm0): state change: need-auth -> prepare (reason 'none', internal state 'managed')
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Simple connect started...
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (4/8): Wait to get fully enabled
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (5/8): Register
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (6/8): Bearer
mar 27 12:57:38 ThinkPad-T470 NetworkManager[11938]: <info> [1522144658.6275] (cdc-wdm0): modem state changed, 'registered' --> 'connecting' (reason: user-requested)
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (7/8): Connect
mar 27 12:57:38 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
mar 27 12:57:40 ThinkPad-T470 NetworkManager[11938]: <info> [1522144660.9244] (cdc-wdm0): modem state changed, 'connecting' --> 'registered' (reason: user-requested)
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Simple connect started...
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (4/8): Wait to get fully enabled
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (5/8): Register
mar 27 12:57:40 ThinkPad-T470 NetworkManager[11938]: <info> [1522144660.9327] (cdc-wdm0): modem state changed, 'registered' --> 'connecting' (reason: user-requested)
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (6/8): Bearer
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (7/8): Connect
mar 27 12:57:40 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.1170] (cdc-wdm0): modem state changed, 'connecting' --> 'registered' (reason: user-requested)
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Simple connect started...
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (4/8): Wait to get fully enabled
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (5/8): Register
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (6/8): Bearer
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.1275] (cdc-wdm0): modem state changed, 'registered' --> 'connecting' (reason: user-requested)
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Simple connect state (7/8): Connect
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
mar 27 12:57:41 ThinkPad-T470 ModemManager[11870]: <info> Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.3099] (cdc-wdm0): modem state changed, 'connecting' --> 'registered' (reason: user-requested)
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <warn> [1522144661.3102] modem-broadband[cdc-wdm0]: failed to connect modem: Unknown error (50)
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.3102] device (cdc-wdm0): state change: prepare -> failed (reason 'unknown', internal state 'managed')
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.3117] policy: disabling autoconnect for connection 'vivacom connection 1'.
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <warn> [1522144661.3137] device (cdc-wdm0): Activation: failed for connection 'vivacom connection 1'
mar 27 12:57:41 ThinkPad-T470 NetworkManager[11938]: <info> [1522144661.3156] device (cdc-wdm0): state change: failed -> disconnected (reason 'none', internal state 'managed')
mar 27 12:57:42 ThinkPad-T470 dbus-daemon[30311]: Activating service name='org.freedesktop.Notifications'
mar 27 12:57:42 ThinkPad-T470 dbus-daemon[30311]: Successfully activated service 'org.freedesktop.Notifications'
Portanto, a falha não é descritiva:
modem-broadband[cdc-wdm0]: failed to connect modem: Unknown error (50)
Consigo me conectar com o mesmo cartão SIM no T450, então o SIM é certamente válido, etc.
Sugestões de outras respostas não ajudaram. Em particular, tentei mudar o modem para o modo QMI, mas depois o sistema se recusou a se registrar em uma rede, então eu tive que mudar para o MBIM de volta, através da interface serial.
Eu também tentei o Ubuntu 18 beta livecd, infelizmente ele não conseguiu se conectar. Qualquer outra coisa que eu poderia tentar?
Obrigado