I tried upgrading to mainline kernel 4.12.10 and the problem still occurs.
Not sure if it matters: I was running Ubuntu previously on this hardware without this issue. I recently installed Windows 10 on this machine and successfully used the Sierra LTE modem from that OS. Then I installed Ubuntu and this problem happens every time.
Note: this problem occurs on every boot up.
I tried upgrading to mainline kernel 4.12.10 and the problem still occurs.
Not sure if it matters: I was running Ubuntu previously on this hardware without this issue. I recently installed Windows 10 on this machine and successfully used the Sierra LTE modem from that OS. Then I installed Ubuntu and this problem happens every time.
Thanks for looking into it.