Ubuntu-Dell-XPS-15-2019

How to install Ubuntu on a Dell XPS 15 model from 2019?

This page will explain how to fix a number of issues with the latest Ubuntu 19.10 running on said laptop. To use the WiFi card a Linux kernel 5.3 or later is required. Ubuntu 18.04.3 LTS should therefore also work with this laptop.

Problems addressed:

• CPU power management
• Changing brightness of OLED screen with brightness keys
• Enabling hardware acceleration for video decoding in Chrome

Things that work out of the box with BIOS 1.3.3:

• WiFi
• Touchpad
• Keyboard backlight

Things that do not work:

• Low power consumption with proper Nvidia graphics drivers and working standby

Installation

To install Ubuntu on a Dell XPS 15 you need to set your Sata Operation in the laptops BIOS from Raid to AHCI. Plugin a USB stick with the image of the latest Ubuntu 19.10 and install from the stick. It is recommended to also install 3rd party software for which one needs to connect the laptop to the internet.

After the installation is complete, run

sudo apt update
sudo apt dist-upgrade -y

to update the system to the latest versions.

BIOS update

If your BIOS version is not up to date the Ubuntu Software manager should offer you a firmware update. This will flash the BIOS upon the next reboot and should thus be done while the laptop is not running on battery. It is recommended to update the BIOS as this ensures working keyboard backlight.

Graphics card driver update

Out of the box the power consumption of the laptop is fairly high at 25 W to 30 W. Apparently, the Nvidia GPU is always active and is not switched off or in power savings mode. This can be rectified with an Ubuntu tool. Run

sudo ubuntu-drivers autoinstall

(Source) If Secure Boot is active, which it should be, then a Machine Owner Key (MOK) needs to be added to the firmware. The tool ubuntu-drivers tool will do this, but you need to specify a password. This password will only be used once upon the next reboot to ensure that you are the one adding a MOK and not some malware (this is the point of Secure Boot).

With the updated drivers the idle power consumption falls to around 12 W, which is still more than the 6 W or so minimum that this laptop can achieve.

Caveat: With the updated drivers the Standby mode seems to break. While the system does go into standby, the GPU "falls off the bus" when waking up. Requiring a hard reboot.

CPU power management

Without further configuration the CPU will run quite hot and will quickly drain the battery. Install powertop and thermald to fix this.

sudo apt install -y powertop thermald

You can start powertop with sudo powertop, navigate to the Tunables section and switch all Bad points to Good. Probably not all of them have a big effect, I have not tried, but the processor related points are absolutely required. However, these changes are not permanent and will be reset at reboot. Instead let us create a service that will change these settings at boot time.

The script and setup are taken from here.

First, create a service with

cat << EOF | sudo tee /etc/systemd/system/powertop.service
[Unit]
Description=PowerTOP auto tune

[Service]
Type=idle
Environment="TERM=dumb"
ExecStart=/usr/sbin/powertop --auto-tune

[Install]
WantedBy=multi-user.target
EOF

and then enable this service to run at boot time with

sudo systemctl daemon-reload
sudo systemctl enable powertop.service

Voila, this should give you a laptop using around 7 W of power in idle (with a black screen).

Note: I also tried running with the energy management tool TLP but found it ineffective.

Screen Brightness (OLED)

When pressing the function keys to change the screen brightness, you will see the Ubuntu brightness icon and its brightness bar changing. However, the brightness of the screen will not change. Apparently, Ubuntu tries to change the background brightness of the screen. Since OLED screens do not have a background illumination, nothing happens.

This is undesirable. Not only will the screen often be too bright, it will also age the display faster. It is possible to change the brightness of the screen from the command line via

xrandr --output eDP-1 --brightness 0.6

to 60 % in this case. The output display eDP-1 might change, if you should use the Nvidia instead of the Intel graphics card. Careful: 0 is black and black on OLED displays is really all black.

The function keys can be mapped to use this command to change the brightness. (Source for Lenovo Thinkpad)

We first create two files that are triggered by the button presses. You need to create a file /etc/acpi/events/dell-brightness-up with the content

event=video/brightnessup BRTUP 00000086 00000000
action=/etc/acpi/dell-brightness.sh up

and a file /etc/acpi/events/dell-brightness-down with the content

event=video/brightnessdown BRTDN 00000087 00000000
action=/etc/acpi/dell-brightness.sh down

Finally, we need a script executing the required xrandr command. Copy this script to /etc/acpi/dell-brightness.sh and grand it execution rights with sudo chmod u+x /etc/acpi/dell-brightness.sh.

After all scripts have been added reload the acpi daemon so that they can have an effect, sudo acpid reload. If the behavior is unexpected, a machine reboot may help.

Note that OLED displays only consume energy and age when the individual pixels are emitting light. Hence, it is advisable to choose dark background colors and install a dark scheme in your browser.

Hardware Acceleration in Chromium

To be able to watch Youtube and other videos from a browser without draining the battery very quickly hardware acceleration for video decoding is required. Unfortunately, neither Googles Chrome(ium) nor Firefox offer hardware acceleration for Linux. There is a private Chromium package on offer that has hardware acceleration enabled, though. Beware that adding private package repositories introduces a security risk and that the following Chromium is based on the less stable beta version. Use at own risk.

Add the private repository and install Chromium via:

sudo add-apt-repository ppa:saiarcot895/chromium-beta
sudo apt update
sudo apt install chromium-browser

For more details and instructions on possibly required driver updates see here.