Lenovo ThinkPad T480s

Device	Status
Intel graphics	Yes
Wireless	Yes
ALSA	no beep
TrackPoint	Yes
Touchpad	Yes
Webcam	Yes
Fingerprint Reader	Yes
Mobile Broadband	Yes
Bluetooth	Yes
Smartcard Reader	Yes
PrivacyGuard	Yes

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.

Hardware

Using kernel 4.15.7-1-ARCH.

Release Date: 01/22/2018
Product Name: 20L7CTO1WW
SKU Number: LENOVO_MT_20L7_BU_Think_FM_ThinkPad T480s
Product Name: 20L7CTO1WW

lspci returns something like:

00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 08)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (rev 07)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 08)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th Gen Core Processor Gaussian Mixture Model
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:15.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0 (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 (rev f1)
00:1c.4 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #5 (rev f1)
00:1c.6 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #7 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #9 (rev f1)
00:1f.0 ISA bridge: Intel Corporation Device 9d4e (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (4) I219-V (rev 21)
04:00.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
05:00.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
05:01.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
05:02.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
06:00.0 System peripheral: Intel Corporation JHL6240 Thunderbolt 3 NHI (Low Power) [Alpine Ridge LP 2016] (rev 01)
3c:00.0 USB controller: Intel Corporation Device 15c1 (rev 01)
3d:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78)
3e:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd Device a808

lsusb returns something like:

Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 013: ID 0bda:0316 Realtek Semiconductor Corp. 
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 5986:2113 Acer, Inc 
Bus 001 Device 003: ID 8087:0a2b Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb (touchscreen model 20L8) returns something like:

Bus 002 Device 002: ID 0bda:0316 Realtek Semiconductor Corp. USB3.0-CRW
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 06cb:009a Synaptics, Inc. 
Bus 001 Device 003: ID 5986:2113 Acer, Inc Integrated Camera
Bus 001 Device 005: ID 04f3:2398 Elan Microelectronics Corp. Touchscreen
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

USB-C DisplayPort

The following adapters were tested:

Dell DA300

Ethernet/HDMI/USB-A/DisplayPort all work. Display output maxes out at 2560x1440@60Hz / 3840x2160@30Hz. 4k@60Hz wasn't possible even with a modeline generated with cvt.

Moshi USB-C to HDMI Adapter

Up to 4k@60Hz Works out of the box with xrandr.

Ugreen USB-C Hub for Macbook

Everything works out of the box (3840x2160@60Hz not tested), most probably all of the variations of this hub work too.

Powersaving

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:

Warning: Changing Thunderbolt BIOS options has been reported to irreversibly brick ThinkPads [1] [2] [3]. This is a BIOS bug. Until there is more information available on that matter (or a fix underway), use these options with care.

• Set "Thunderbolt BIOS Assist Mode" to "Enabled" in the EFI firmware interface. This seems to reduce number of idle wakeups.
  • However, kernel versions since 4.19+ should support it natively ([4]), and some power consumption improvements is reported if this is switched to "Disabled" [5].
• 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 don't want to disable it in bios because you use it semi-regularly, you can turn it off by unbinding its driver using this command:

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

You can then turn the reader back on by running:

echo "2-3" | sudo tee /sys/bus/usb/drivers/usb/bind

Fingerprint Reader

The fingerprint sensor 06cb:009a is not supported by libfprint.

There is a project python-validity based on open-fprintd that support 06cb:009a see [6].

Warning: Some issues or delay are known after suspend/resume. [7]

Install the python-validity^AUR or python-validity-git^AUR and enroll your device:

 fprintd-enroll

Refer to Fprint#Configuration for configuration.

Troubleshooting

Thermal Throttling

There are reported throttling issues for Lenovo T480/T480s/X1C6 notebooks.[8]

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.

Install the throttled package and enable the lenovo_fix.service.[9]

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.

PrivacyGuard

The PrivacyGuard feature is referred to as LCD Shadow [10] and was introduced in Linux 5.4.[11]

To enable or turn on the LCD shadow:

echo 1 | sudo tee /proc/acpi/ibm/lcdshadow

Conversely, use 0 to disable it:

echo 0 | sudo tee /proc/acpi/ibm/lcdshadow

Fix freezes/hangs on QT applications (with Intel driver)

See Intel graphics#AccelMethod.

See also

• T480s install video playlist