I just set up WWAN on my X1 carbon. It was a little tricky, and I hit some errors I haven’t found documented elsewhere on the net.
I didn’t attempt to activate the SIM on linux. It’s probably possible, but I wasn’t familiar with the tools required, and din’t want to be in the AT&T store any longer than I had to be. So, I booted into Windows before heading over.
I started off following the arch wiki guide on the X1C9
https://wiki.archlinux.org/title/Lenovo_ThinkPad_X1_Carbon_(Gen_9)
Supplemented with
https://wiki.archlinux.org/title/Mobile_broadband_modem
pacman -S modemmanagerFirst start modemmanager
sudo systemctl start ModemManager
List available modems with
$ mmcli -M ⏎
/org/freedesktop/ModemManager1/Modem/1 [foxconn] MBIM [105B:E0AB]
Modem details
$ mmcli -m 1 ⏎
-----------------------------------
General | path: /org/freedesktop/ModemManager1/Modem/1
| device id: [redacted]
-----------------------------------
Hardware | manufacturer: foxconn
| model: MBIM [105B:E0AB]
| firmware revision: T99W175.F0.0.0.5.7.AT.008
| 077
| carrier config: ATT
| carrier config revision: 0A000308
| h/w revision: Qualcomm Snapdragon X55 5G
...
Then attempt to enable the modem
mmcli -m 1 -e --verbose
[04 Sep 2021, 23:05:19] [Debug] ModemManager process found at ':1.99'
[04 Sep 2021, 23:05:19] [Debug] Assuming '1' is the modem index
[04 Sep 2021, 23:05:19] [Debug] Modem found at '/org/freedesktop/ModemManager1/Modem/1'
[04 Sep 2021, 23:05:19] [Debug] Synchronously enabling modem...
error: couldn't enable the modem: 'GDBus.Error:org.freedesktop.ModemManager1.Error.Core.Retry: Invalid transition'
This was the main bit of trouble I ran into in this process. I eventually found tools to debug the connection:
First shut down ModemManager
sudo systemctl stop ModemManager
sudo systemctl disable ModemManager
Then run it manually with –debug
sudo ModemManager --debug
Then re-attempt to enable the modem in a new terminal
mmcli -m 1 -e --verbose
After running that mmcli command, I found in the output of ModemManager --debug
>>>>>> Fields:
>>>>>> HwRadioState = 'off'
>>>>>> SwRadioState = 'on'
ModemManager[9864]: <warn> [1630811585.620885] [modem0] Cannot power-up: hardware radio switch is OFF
ModemManager[9864]: <debug> [1630811585.620902] [modem0] couldn't update power state: Invalid transition
Googling for “Cannot power-up: hardware radio switch is OFF” lead me to:
https://ex0ns.me/lenovo-x1c6-em7455.html
Which mentioned trying to send some AT commands to the modem. That didn’t end up being helpful, but if you would like to mess with AT commands, I was able to do so with socat to the /dev/wwan0p3AT device.
sudo socat - /dev/wwan0p3AT,crnl ⏎
AT
OK
The blog post mentions an AT command that can be used to disable the hardware switch. That AT command didn’t work for me with this modem.
However, the article also mentions:
as this is a non-standard WWAN card, the firmware fails to detect its features and do not export it in RFKILL
It appears this modem is standard, and is exported to rfkill.
$ rfkill ⏎
ID TYPE DEVICE SOFT HARD
0 bluetooth tpacpi_bluetooth_sw blocked unblocked
1 wwan tpacpi_wwan_sw blocked unblocked
3 wlan phy0 unblocked unblocked
Enable wwan with rfkill:
rfkill unblock wwan
Then try enabling again:
$ mmcli -m 0 -e --verbose
[04 Sep 2021, 23:23:39] [Debug] ModemManager process found at ':1.145'
[04 Sep 2021, 23:23:39] [Debug] Assuming '0' is the modem index
[04 Sep 2021, 23:23:39] [Debug] Modem found at '/org/freedesktop/ModemManager1/Modem/0'
[04 Sep 2021, 23:23:39] [Debug] Synchronously enabling modem...
successfully enabled the modem
Then try connecting:
$ mmcli -m 0 --simple-connect="apn=broadband"
successfully connected the modem
At this point, you can set up a new mobile broadband connection in NetworkManager.