Lenovo ThinkPad T480s
This article covers the installation and configuration of Arch Linux on a Lenovo T480s laptop. For the most part things work out-of-the-box, but there are some features that are unavailable.
For a general overview of laptop-related articles and recommendations, see Laptop.
Without special configuration and with default firmware settings, power usage is a bit high (around 7,5W in idle). There are a few knobs to improve battery life:
- Set "Thunderbolt BIOS Assist Mode" to "Enabled" in the EFI firmware interface. This seems to reduce number of idle wakeups.
- Disable unused peripherals under "Security" -> "I/O port access" in the firmware. This especially applies to the SD/MMC-cardreader, which seems to drain some power even when idle
As of Kernel 4.15, DisplayPort PSR (Panel self refresh) is disabled by default and broken when forcibly enabled (system hangs after a few seconds, display lag). 4.17-rc1 seems to improve a lot in this regard, but PSR still sometimes causes the screen to freeze for a few seconds.
SD card reader
According to various reports the SD card reader drains several watts of power. If you do not want to disable it in bios because you use it semi-regularly, you can turn it off by unbinding its driver using this command:
# tee /sys/bus/usb/drivers/usb/unbind <<< 2-3
You can then turn the reader back on by running:
# tee /sys/bus/usb/drivers/usb/bind <<< 2-3
The fingerprint sensor
06cb:009a is not supported by libfprint.
suspend/resume. See Fingerprint not working after waking up from suspend in the README to resolve this issue.
Install the AUR or AUR and enroll your device:
Refer to Fprint#Configuration for configuration.
There are reported throttling issues for Lenovo T480/T480s/X1C6 notebooks.
This script forces the CPU package power limit (PL1/2) to 44 W (29 W on battery) and the temperature trip point to 95 'C (85 'C on battery) by overriding default values in MSR and MCHBAR every 5 seconds (30 on battery) to block the Embedded Controller from resetting these values to default.
It is recommended to also undervolt the CPU (Undervolting CPU#intel-undervolt). Most Kaby Lake R chips are able to easily undervolt to -100mV or more, which significantly helps to keep the device from thermal throttling. Throttled also provides undervolting capabilities and will overwrite the undervolt settings applied by intel-undervolt when it updates settings if both services are enabled.
To enable or turn on the LCD shadow:
# tee /proc/acpi/ibm/lcdshadow <<< 1
0 to disable it:
# tee /proc/acpi/ibm/lcdshadow <<< 0