Lenovo ThinkPad X1 Carbon (Gen 6)

From ArchWiki
Jump to navigation Jump to search
Tip: A great resource for thinkpads is https://www.thinkwiki.org/wiki/ThinkWiki

The Lenovo ThinkPad X1 Carbon, 6th generation is an ultrabook introduced in early 2018. It comes in several variants(20KH* and 20KG*) and features a 14" screen, 8th-gen Intel Core processors and integrated Intel UHD 620 graphics.

To ensure you have this version, install the package dmidecode and run:

# dmidecode -s system-version
ThinkPad X1 Carbon 6th
Device Working Modules
Intel graphics Yes i915, (intel_agp)
Wireless network Yes iwlmvm
Native Ethernet with included dongle Yes ?
Mobile broadband Fibocom L850-GL Yes¹ cdc_mbim after MBIM-switch (from PCIe)
Mobile broadband Sierra EM7455 Yes cdc_mbim, cdc_wcm, cdc_ncm
Audio Yes snd_hda_intel
Touchpad Yes psmouse, rmi_smbus, i2c_i801
TrackPoint Yes psmouse, rmi_smbus, i2c_i801
Camera Yes uvcvideo
Fingerprint Reader No² ?
Power management Yes³ ?
Bluetooth Yes⁴ btusb
NFC No⁶ ?
microSD card reader Yes scsi_mod
Keyboard Backlight Yes thinkpad_acpi
Function/Multimedia Keys Yes ?
Thunderbolt 3 eGPU Yes⁵ nvidia
  1. No working Linux driver for Fibocom L850-GL. See this thread and this thread for more info. MBIM-Switch
  2. The Validity90 project began reverse engineering the reader, but scanning does not yet work (06cb:009a).
  3. S3 suspend requires changes to BIOS settings - see section on suspend issues.
  4. See this blog post for improvements to reliability.
  5. Internal monitor acceleration does not appear to be supported.
  6. Connected via I2C, support was discussed in the libnfc project.


The most convenient way to install Arch Linux is by disabling "Secure Boot" Security -> Secure Boot - Set to "Disabled". However it is possible to self-sign your kernel and boot with it enabled. For further information have a look at the Secure Boot article.

In case your efivars are not properly set it is most likely due to you not being booted into UEFI. Should the problem persist be sure to consult the UEFI#UEFI variables section.


Note: In the BIOS setup menu under Security -> UEFI BIOS Update Option, both Flash BIOS Updating by End-Users and Windows UEFI Firmware Update must be enabled at the time of an update.

Automatic (Linux Vendor Firmware Service)

In August of 2018 Lenovo has joined the Linux Vendor Firmware Service(LVFS) project, which enables firmware updates from within the OS. BIOS updates (and other firmware such as the Thunderbolt controller) can be queried for and installed through fwupd.

Manual (fwupdmgr)

Lenovo provides a cabinet file that can be directly installed with fwupdmgr. Take the most recent .cab file from the Lenovo ThinkPad X1 Carbon (Gen 6) driver website.

  1. Make sure the AC adapter is firmly connected to the target computer.
  2. Launch Terminal.
  3. Move to the directory where the cabinet file was placed.
  4. Run fwupdmgr install xxxxxxxx.cab to schedule firmware update.
  5. Restart the system.
  6. The computer will be restarted and the UEFI BIOS will be updated.

Manual (El Torito)

Download the latest BIOS update ISO. Obtain geteltoritoAUR and run geteltorito.pl -o bios-update.img n23ur12w.iso on the downloaded ISO file to create a valid El Torito image file, then flash this file on a USB drive via dd like you would flash Arch installation media. For further information see flashing BIOS from Linux.

The ThinkPad X1 Carbon supports setting a custom splash image at the earliest boot stage (instead of the red "Lenovo" logo), more information can be found in the README.TXT located in the FLASH folder of the update image. This only needs to be done once, as subsequent UEFI upgrades will ask whether you wish to keep your custom logo.

Once the USB drive is flashed, the logo file can be placed in to the root directory of the flash drive.

Suspend issues

Since BIOS version 1.30, the X1 Carbon supports S3 mode when enabled in the BIOS menu (choose "Linux" sleep mode instead of the default "Windows 10"). See #Automatic (Linux Vendor Firmware Service) for instructions to update and verify your BIOS version.

Enabling S3

To enable S3 support, make sure you have at least BIOS version 1.30 installed. Then, go into the BIOS configuration, and Config -> Power -> Sleep State - Set to "Linux". This should make S3 available. To verify, after making the changes in the BIOS configuration, boot into Linux, and run:

 dmesg | grep -i "acpi: (supports"

to make sure that S3 is now available.

Verifying S3

To check whether S3 is recognized and usable by Linux, run:

dmesg | grep -i "acpi: (supports"

and check for S3 in the list.

S3 Suspend Bug with Bluetooth Devices

Occasionally your Thinkpad will wake up immediately or a few seconds after suspending with certain bluetooth devices added. To prevent this, remove the devices or disable bluetooth before suspending.

Disabling the memory card reader

You might also need to disable the Realtek memory card reader (which appears to use a constant 2-3 W) either via the BIOS or via

# echo "2-3" | tee /sys/bus/usb/drivers/usb/unbind

BIOS configurations

  • Config -> Thunderbolt BIOS Assist Mode - Set to "Enabled". When disabled, on Linux, power usage appears to be significantly higher because of a substantial number of CPU wakeups during s2idle.

Failed to start Suspend

Symptom: The machine starts entering suspend but comes back online immediately when phone charges through USB-C.

Note: just a plain USB-C cable - without attached external device - can cause that too.

# journalctl -p err -u systemd-suspend
Failed to suspend system. System resumed again: Device or resource busy
$ dmesg -Tl err
[Mon Nov 11 20:18:03 2019] PM: pci_pm_suspend(): hcd_pci_suspend+0x0/0x30 returns -16
[Mon Nov 11 20:18:03 2019] PM: dpm_run_callback(): pci_pm_suspend+0x0/0x130 returns -16
[Mon Nov 11 20:18:03 2019] PM: Device 0000:00:14.0 failed to suspend async: error -16
[Mon Nov 11 20:18:04 2019] PM: Some devices failed to suspend, or early wake event detected 

Solution: Block USB devices from waking up the computer.

Check that grep XHC /proc/acpi/wakeup shows enabled. If yes, disable XHC wakeup with:

 echo XHC | sudo tee /proc/acpi/wakeup

Now, test your computer. If your problem is solved then you have to persist the change as it would get lost on reboot.

Persistent Solution

There is no way to persist the config through a configuration file. So create the following systemd unit file and enable the service.

Description=Fixes failing suspend by disabling wakeup through USB

ExecStart=/bin/bash -c 'grep --silent '^XHC.*disabled' /proc/acpi/wakeup || echo XHC > /proc/acpi/wakeup'


Power management/Throttling issues

Due to wrong configured power management registers the CPU may consume a lot less power than under windows and the thermal throttling occurs at 80°C (97°C when using Windows, see T480s throttling bug).

There is a post in the official Lenovo forum to inform Lenovo about this issue, and a Lenovo employee has confirmed that they're actively working on a fix but also said that it may take some time.

Throttling fix

An easy package has been written to address the problem until Lenovo completes the OS agnostic fix for the X1C6.

Install throttled, then run:

# systemctl enable --now lenovo_fix.service

The script also supports more advance thermal/performance features including CPU undervolting. See the repository README.md for details.

Note: If you installed thermald, it may conflict with the throttling fix in this package. Consider disabling thermald or otherwise work around this.

Audio crackling

When charging you may hear crackling noise while listening to audio. The work around for this issue is to disable one of the PINs:

# hda-verb /dev/snd/hwC0D0 0x1d SET_PIN_WIDGET_CONTROL 0x0

There is also a kernel patch for this issue, which can be found here.

Microphone distorted due to automatic adjustment

If your microphone volume creeps up automatically and causes the sound to be distorted, you can fix it by disabling mic boost. See Pulse Audio for details.

Built-in speakers low volume workaround

If your ThinkPad X1 Carbon (Gen 6) built-in speakers are limited to a maximum of about 20% volume even though the volume is set at 100%, try adding the following parameter to the snd_hda_intel module, which can be set through a file in /etc/modprobe.d/, e.g.:

options snd-hda-intel model=nofixup
Note: This stops the LEDs on the mute and mic-mute buttons from working.

Wireless WAN / LTE

ThinkPad X1 Carbon (Gen 6) is exclusively shipped with a Fibocom L850-GL LTE modem, which is currently not supported out of the box under Linux.

It is normally impossible to swap the LTE modem for a supported one due to BIOS-level restrictions ("whitelists" of allowed M.2 expansion cards) implemented in all modern Lenovo laptops. However, a method has been found to configure any Sierra Wireless EM73xx/EM74xx modem to "evade" the whitelist checks, so these modems can be used normally.

Take a look at ThinkPad mobile internet: Getting around BIOS-level whitelist restrictions for instructions.

See also the work done in github: Tools for the Fibocom L850-GL / Intel XMM7360 LTE modem, github: Kernel module for Fibocom L850-GL / Intel XMM7360 LTE modem and Lenovo Forums: WWAN Fibocom L850-GL and Linux support.


Install NetworkManager and network-manager-applet to make your life easier founding the correct APN for your SIM card.


Keyboard Fn Shortcuts

  • Fn+4 sends XF86Sleep (puts computer to sleep by default)
  • Fn+S sends Alt_L+Sys_Req
  • Fn+P sends Pause
  • Fn+B sends Control_L+Break
  • Fn+K sends Scroll_Lock
  • Fn+Space toggles the keyboard backlight
  • Fn by itself sends XF86WakeUp (wakes computer from sleep by default)

Special buttons

Some special buttons are not supported by X server due to keycode number limit.

Key combination Scancode Keycode Note
Fn+F11 0x49 374 KEY_KEYBOARD Not recognized in Wayland
Fn+F12 0x45 364 KEY_FAVORITES Recognized correctly on Wayland

You can remap unsupported keys so that they can be detected and mapped in X using udev hwdb:

Note that prog1 and prog2 map to KEY_PROG1 and KEY_PROG2 in /usr/include/linux/input-event-codes.h. You can use any key code with a defined value less than 255. The keycode hwdb expects is the lowercased text following KEY_ in the above input event codes header file. eg: KEY_COFFEE would be coffee.

evdev:name:ThinkPad Extra Buttons:dmi:bvn*:bvr*:bd*:svnLENOVO*:pn*

To make the changes take effect:

# udevadm hwdb --update
# udevadm trigger --sysname-match="event*"

To disable the red LED in the ThinkPad logo on the cover:

1. Enable writing to the embedded controller registers by adding the kernel parameter ec_sys.write_support=1. If you use UEFI boot, you can add this parameter in /boot/efi/loader/entries/arch.conf under "options".

2. Then, you can disable directly the LED with this command:

# echo -n -e "\x0a" | dd of="/sys/kernel/debug/ec/ec0/io" bs=1 seek=12 count=1 conv=notrunc 2> /dev/null

To disable the LED at startup, you can create a systemd service:

1. Create a sh script (/root/disable_led.sh for instance) and put this :

echo -n -e "\x0a" | dd of="/sys/kernel/debug/ec/ec0/io" bs=1 seek=12 count=1 conv=notrunc 2> /dev/null

2. Create a new service unit file in /etc/systemd/system called "led.service", and insert the following:

Description=Disabling thinkpad led



3. Start and enable this service:

# systemctl start led.service
# systemctl enable led.service

HDR Display Color Calibration

For models with the 1440p HDR display, the default color profile can be corrected under Gnome using an ICC calibration provided by notebookcheck.net's review.

 wget https://www.notebookcheck.net/uploads/tx_nbc2/B140QAN02_0.icm
 colormgr import-profile B140QAN02_0.icm

This will import the ICC profile, and next you'll need to activate it for your display. Find your display's object path:

 colormgr get-devices | sed -rn 's/Object Path:\s*(.*eDP1.*)/\1/p'

And your new color profile object path:

 colormgr get-profiles | grep -4 -i B140QAN02

And finally activate the profile and set it as the default for this display:

 colormgr device-add-profile <device object id> <profile object id>
 colormgr device-make-profile-default <device object id> <profile object id>

You can verify the profile is active by running colormgr get-devices.

Intel Graphics UHD 620 issues

  • Enable GuC/HuC firmware loading suggests to load GPU firmware with warning. However, on Wayland for Carbon X1 gen 6 it cause GPU hang problem. Issues can be reflected as: a) crashing GPU process of Chrome / Chromium / Electron apps and subsequent host freezing; b) crashing of Gnome / Wayland with possibility to reboot via second virtual terminal; c) just host freezing. In dmesg the following can be observed:
 kernel: [drm] GPU HANG: ecode 9:0:0x85dffffd, in chrome [18418], reason: hang on rcs0, action: reset
 kernel: [drm] GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
 kernel: [drm] Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
 kernel: [drm] drm/i915 developers can then reassign to the right component if it's not a kernel issue.
 kernel: [drm] The gpu crash dump is required to analyze gpu hangs, so please always attach it.
 kernel: [drm] GPU crash dump saved to /sys/class/drm/card0/error
 kernel: i915 0000:00:02.0: Resetting rcs0 for hang on rcs0

Note that, first line changes depending on the source of crashing application, but the result is the same, so issue is with GPU / firmware. Basically don't enable GuC / HuC firmware loading, at least if on Wayland. There are a number of similar issues reported including #108717.

  • The modesetting driver causes tearing in some situations. You can install the xf86-video-intel driver instead and enable the "TearFree" option in your configuration file:
Section "Device"
  Identifier  "Intel Graphics"
  Driver      "intel"
  Option      "TearFree" "true"

GNOME Wayland not available

If you haven't added the i915 to the MODULES list in /etc/mkinitcpio.conf (e.g. following the full disk encryption requirements below), you may be unable to run Wayland on kernel 4.20 (the gnome on Wayland option might not be present on GDM). Adding i915 to the MODULES list in /etc/mkinitcpio.conf and regenerating the ramdisk solves this issue.

TrackPoint and Touchpad issues

Note: Some models of the 6th generation X1 Carbon seem to have issues with the TrackPoint and Touchpad working at the same time.
Note: The following parameter will only work for kernel versions after v4.14. Fore more information, see Lenovo ThinkPad X1 Carbon (Gen 5)#Trackpoint/Trackpad not working.

To get the TrackPoint and Touchpad to work at the same time, add synaptics_intertouch=1 to the psmouse kernel module options, for example in the cmdline of the boot loader:

 [...] root=/dev/sda1 rw psmouse.synaptics_intertouch=1 [...]

or by editing /etc/modprobe.d/psmouse.conf:

 options psmouse synaptics_intertouch=1
Note: When using TLP with default powersaving settings, there might be occasional hiccups such as dropouts of tap-to-click functionality for the Touchpad, as well as the TrackPoint not surviving suspends and needing to be re-initialized.

Reconnecting a dead trackpad can be done via the following command, as the root user:

echo -n "none" | tee /sys/bus/serio/devices/serio1/drvctl
echo -n "reconnect" | tee /sys/bus/serio/devices/serio1/drvctl

A bug in the libinput library that caused dropouts of the tap-to-click functionality of the touchpad on the X1 Carbon 6th Gen has been fixed in libinput 1.11.2, which was released on 3 July 2018.

Thunderbolt dock

Plugable USB-C Mini Docking Station with 85W Power Delivery UD-CAM

If you are using an external plugable UD-CAM thunderbolt dock connected to the laptop through its USB-C thunderbolt port, you might experience random disconnections (external monitor, bluetooth and ethernet) with this kind of error in dmesg :

pcieport 0000:05:00.0: BAR 13: no space for [io  size 0x3000]

It should be noted that bolt is not working with this UD-CAM dock.

To avoid random disconnection, proceed as followed by editing the bios and TLP

Bios settings

You should then look at your bios settings :

  • Wake by thunderbolt : enable
  • Security level : no security
  • Pre-boot ACL option : enable

TLP blacklisting devices from USB autosuspend

If you are using TLP you have to edit /etc/default/tlp and make sure that you exclude all dock devices from USB autosuspend as followed :

USB_BLACKLIST="0000:1111 2222:3333 4444:5555"

Then reboot and your dock should work correctly.

Lenovo dock

Some problems can be caused by outdated dock firmware. Updates are not supplied by LVFS, use "Firmware for Windows" from the dock support page.

Full-disk encryption

LUKS: Ramdisk module

With LUKS for root, i915 needs to be loaded in ramdisk in order to access the password prompt. Add i915 to MODULES list in /etc/mkinitcpio.conf and regenerate the ramdisk.

OPAL: Hardware based full-disk encryption

See Self-encrypting drives (Confirmed working)



s-tui (s-tui): an aesthetically pleasing and useful curses-style interface that shows graphs of CPU frequency, utilization, temperature, and power consumption. It also has a built in stress tester.

intel_gpu_top (intel-gpu-tools): gives you some top-like info for the integrated GPU. This can be quite useful in diagnosing GPU acceleration issues.

powertop (powertop): provides detailed information about CPU power consumption and recommendations on how to improve it.

tlp-stat (tlp): a much simpler alternative to remembering which cat /sys/devices/system/* to run in many cases. It can give very detailed, structured information about components like the battery, processor, graphics card, etc.

nvme issues

There is an issue with nvme installed in ThinkPad X1 Carbon (Gen 6) resulting in device failure. Be sure to update firmware or reach out to lenovo support for replacement.


Additional resources