I also have a TP T450s with a Sierra EM 7345. It appears that this piece of hardware is generally a bit unstable:
http://askubuntu.com/questions/580167/wwan-modem-disabeling-by-itself-ubuntu-14-10-lenovo-t440s-sierra-wireless-em7 https://forums.lenovo.com/t5/ThinkPad-Tablets/Thinkpad-10-EM7345-stops-working/m-p/1742115/highlight/true#M28656
I also experienced the card being or not being available after reboots.
I was successful bringing up the card by unloading and loading the cdc_* kernel modules (if necessary, several times):
modprobe -r cdc_mbim cdc_ncm cdc_wdm modprobe cdc_mbim cdc_ncm cdc_wdm
Very unsatisfying, but at least a way to get it working when needed.
I would still be interesting to see a Ubuntu dev's opinion on this issue, especially as the T450s is a Ubuntu-certified machine.
I also have a TP T450s with a Sierra EM 7345. It appears that this piece of hardware is generally a bit unstable:
http:// askubuntu. com/questions/ 580167/ wwan-modem- disabeling- by-itself- ubuntu- 14-10-lenovo- t440s-sierra- wireless- em7 /forums. lenovo. com/t5/ ThinkPad- Tablets/ Thinkpad- 10-EM7345- stops-working/ m-p/1742115/ highlight/ true#M28656
https:/
I also experienced the card being or not being available after reboots.
I was successful bringing up the card by unloading and loading the cdc_* kernel modules (if necessary, several times):
modprobe -r cdc_mbim cdc_ncm cdc_wdm
modprobe cdc_mbim cdc_ncm cdc_wdm
Very unsatisfying, but at least a way to get it working when needed.
I would still be interesting to see a Ubuntu dev's opinion on this issue, especially as the T450s is a Ubuntu-certified machine.