Thinkpad T480s

Table of Contents

• 1. Dualboot with Arch, Windows 10 and disk encryption
• 2. Nvidia Optimus & Linux
  • 2.1. Bumblebee
• 3. HiDPI & Linux
• 4. CPU throttling fix
• 5. Power Management
• 6. Other
  • 6.1. Special Buttons

1. Dualboot with Arch, Windows 10 and disk encryption

See here.

2. Nvidia Optimus & Linux

• https://www.youtube.com/watch?v=5nGbWE-pvIE

• https://wiki.archlinux.org/index.php/PRIME

• https://wiki.archlinux.org/index.php/NVIDIA_Optimus

2.1. Bumblebee

1. pacman -Syu mesa xf86-video-intel nvidia bumblebee

2. sudo gpasswd -a user bumblebee (replace user with your username)

3. sudo systemctl enable bumblebeed.service

4. If tlp is installed and enabled:

   • Find the address of the GPU with lspci | grep 3D (First column, such as 01:00.0)

   • Edit /etc/default/tlp:

     ...
     RUNTIME_PM_BLACKLIST="01:00.0"
     ...

5. Reboot

References

• http://lenovolinux.blogspot.com/2018/02/bumblebee-on-lenovo-t440p-nvidia-gt.html?m=1

• https://wiki.archlinux.org/index.php/Bumblebee

3. HiDPI & Linux

Adding this to my ~/.Xresources has solved 90% of scaling for me (120 for 125% scaling):

~/.Xresources

Xft.dpi: 120
Xft.autohint: 0
Xft.lcdfilter:  lcddefault
Xft.hintstyle:  hintfull
Xft.hinting: 1
Xft.antialias: 1
Xft.rgba: rgb

...

References

• https://wiki.archlinux.org/index.php/HiDPI

• https://wiki.archlinux.org/index.php/Xorg#Display_size_and_DPI

4. CPU throttling fix

References

• https://www.reddit.com/r/thinkpad/comments/870u0a/t480s_linux_throttling_bug/

• https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Power_management.2FThrottling_issues

• https://github.com/erpalma/lenovo-throttling-fix

5. Power Management

• Packages:

  • tlp

  • acpi_call

References

• http://thinkwiki.de/TLP_-_Linux_Stromsparen

• https://wiki.archlinux.org/index.php/TLP

• https://wiki.archlinux.org/index.php/Fan_speed_control

• https://wiki.archlinux.org/index.php/Undervolting_CPU

• https://wiki.archlinux.org/index.php/PHC

• https://wiki.archlinux.org/index.php/CPU_frequency_scaling

• https://wiki.archlinux.org/index.php/Laptop

• https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_T480s

• https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_T480

6. Other

6.1. Special Buttons

Some buttons (Fn+F11, Fn+F12) have a keycode above 255 and are thus not supported by X. They can be remapped using:

6.1.1. ACPI Events

1. pacman -Syu acpi

2. sudo systemctl enable acpid.service

3. Modify /etc/acpi/handler.sh:

   /etc/acpi/handler.sh

   # ...
       ibm/hotkey)
         case "$4" in
             00001311)
                 logger 'Favorites'
                 /etc/acpi/actions/favorites-key.sh
                 ;;
             00001315)
                 logger 'Keyboard'
                 /etc/acpi/actions/keyboard-key.sh
                 ;;
             *)
                 logger "ACPI action undefined: $1 : $2 : $3 : $4"
                 ;;
     esac
     ;;
   # ...

References

• https://wiki.archlinux.org/index.php/acpid

6.1.2. udev hwdb

1. Modify /etc/udev/hwdb.d/90-thinkpad-keyboard.hwdb:

   /etc/udev/hwdb.d/90-thinkpad-keyboard.hwdb

   evdev:name:ThinkPad Extra Buttons:dmi:bvn*:bvr*:bd*:svnLENOVO*:pn*
    KEYBOARD_KEY_45=prog1
    KEYBOARD_KEY_49=prog2

2. sudo udevadm hwdb --update

3. sudo udevadm trigger --sysname-match="event*"

References

• https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_T480#Special_buttons

• https://wiki.archlinux.org/index.php/Map_scancodes_to_keycodes