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I'm having some trouble configuring my laptop's displays to behave as desired. My laptop is an ASUS Zenbook ux535, and it has an additional screen built into the touchpad. On Windows, this screen is kept off until I log in, at which point it can be turned on and used as a regular screen.

I'd like to recreate this behaviour on Linux. I've partially achieved it thus far. Once my display server (Wayland using KWin) is active, it behaves as desired. However, until this point, the display is on, and anything displayed on it is rotated 90° (due to this being the native orientation of the display). This behaviour is particularly distracting in Console mode, and during my boot sequence, moreso since I've been trying to setup a Plymouth boot video.

I need a way to disable this display by default on boot, that leaves it able to be enabled once I'm logged into my DE. I've tried using KMS, which is able to disable it as desired, but I can't find a way of re-enabling it once in the DE.

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2 Answers 2

Reset to default
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If you're using grub to boot, identify the screen name and enable only the screen you want to keep from grub parameter in adding to variable LINUX_CMD_LINE_DEFAULT:

video=VGA-1:d or video=LVDS-1:d

or ... depending on the screen name.

You may find this variable in /etc/default/grub

You may find the screen name with:
xrandr -q

and don't forget to upgrade grub config with something like grub-mkconfig

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  • Thanks for the response, I've tried this, but I'm then unable to re-enable the display once booted, I need to be able to turn on the display once in my DE via a shell script. Do you know how to do this? Commented Sep 17 at 18:35
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I was eventually able to do this by exploring the documented behaviour of my specific device. If I write 0 into the brightness field of the device in /sys, it will turn off as if it's been unplugged, while leaving the kernel module active to be able to turn it back on. I set up a systemd service in my initrd to do this (linked to a udev rule that detects the device), and achieved the behaviour I wanted.

This probably won't work in the general case, as the device needs the brightness=0 -> Off logic, but if anyone's trying to do this with an Asus Screenpad, this is how to do it.

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  • Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center. Commented Sep 23 at 13:17

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