A bit late, but nevertheless: With quite some effort I got my Sierra EM7345 to work.
The EM7345 seems to be infamous for buggy firmware, one should install the latest, V1.2 seems essential. Unfortunately this needs Lenovo's Windows, Lenovo Service Bridge, some other internet connection, and having a working SIM card inserted!
Have now firmware FIH7160_V1.2_WW_01.1616.01.
On Linux, the EM7345 seems to need mbim mode. Manual one-shot:
Code: Select all
sudo rmmod cdc_mbim # uses cdc_ncm
sudo rmmod cdc_ncm
sudo modprobe cdc_ncm prefer_mbim=Y # restart with this option
sudo modprobe cdc_mbim # restart
echo '1-4' | sudo tee /sys/bus/drivers/usb/unbind # power-cycle the modem
echo '1-4' | sudo tee /sys/bus/drivers/usb/bind # at USB bus 1 device 4
# for your machine, do usb-devices and look for Sierra's Bus=? and Dev#= ?
ls /dev # now must show a newly added cdc-wdm0
For permanence, create a /etc/modprobe.d/em7345.conf containing —
options cdc_ncm prefer_mbim=Y
All this was necessary to get the modem to connect at all.