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xypnox
Asked: 2018-04-29 07:35:13 +0800 CST

Display brightness cannot be adjusted 18.04

  • 772

I have recently installed Ubuntu mate 18.04 on my XPS 15 9560. I cannot adjust the display brightness through any means. I have tried the following:

  1. Set the acpi_backlight=vendor in boot parameters
  2. used xbacklight, which gives the following results

.

xypnox@xypnox-xps:~$ xbacklight -set 50
No outputs have backlight property

also I followed another question at xbacklight: No outputs have backlight property - No /sys/class/backlight folder, and the output for sudo find /sys/ -type f -iname '*brightness*' is 

xypnox@xypnox-xps:~$ sudo find /sys/ -type f -iname '*brightness*'
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness_hw_changed
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/max_brightness
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/brightness
/sys/module/video/parameters/brightness_switch_enabled
/sys/module/i915/parameters/invert_brightness
backlight laptop display brightness ubuntu-mate

10 Answers

  1. An alternative method is to install a PPA and brightness APP which also adjusts gamma - AWESOME!, and ... for any individual screen TOO!

    Here are the 3 simple steps:

    $ sudo add-apt-repository ppa:apandada1/brightness-controller
$ sudo apt update
$ sudo apt install brightness-controller

    Then find it ...

    Brightness Controller

    in your App's/Accessories

    Always Trying to help, Mark

    • 7

  2. I had the same issue on a Dell XPS 13. Found this link that solved the problem for me : https://bugs.archlinux.org/task/58296#comment168869

    What I did:

    • changed the content of /etc/default/grub by adding video.only_lcd=0 to GRUB_CMDLINE_LINUX_DEFAULT
    • updated grub with sudo update-grub

    After restarting the laptop, I was able to control the brightness.

    • 6

  3. I had the same problem some years ago and was having the same problem again after installing ubuntu 18.04. it was a kernel problem then, and i think it may be a kernel problem now.

    After updating the kernel the problem was fixed for me.

    To update kernel see: Updating kernel question

    To download last stable kernel (which worked for me): http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.16.6/

    In my case i downloaded:

      linux-headers-4.16.6-041606_4.16.6-041606.201804300418_all.deb

  linux-headers-4.16.6-041606-generic_4.16.6-041606.201804300418_amd64.deb

  linux-image-unsigned-4.16.6-041606-generic_4.16.6-041606.201804300418_amd64.deb

  linux-modules-4.16.6-041606-generic_4.16.6-041606.201804300418_amd64.deb
    • 2

  4. I've been struggling for the past week on trying to get Ubuntu working on my Dell XPS 15 9570 and I've had it working for a while with nomodeset but it's been killing my eyes having the display stuck on full brightness.

    I finally fixed it today! I updated my kernel to 4.17 (http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17/) which was last updated two days ago and then restarted, and then finally restarted again without the nomodeset option (and didn't have to replace it with anything) and the display works now!!!

    Hope this helps :)

    • 1

  5. I have an XPS 15, and the following solved it for me:

    1. Updating to the latest kernel (4.17.5 is the one I used, following instructions from this answer)
    2. Reboot
    3. Remove any video options (nomodeset, video.only_lcd=0, etc.) from the GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub file.
    4. Run update-grub to update
    5. Reboot

    This made it possible to adjust from the keyboard and made "night mode" actually change screen colors.

    • 1
  6. Best Answer

    I have finally found the solution to the problem. There display drivers for Ubuntu did not work out of the box for me. I started fresh from a 18.04.1 release and used nomodeset to boot into the live USB. Obviously, I could not set the brightness. I installed regularly and rebooted.

    I installed the latest nvidia drivers from the ppa: https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa

    Then I restarted the system and also added the boot parameters acpi_rev_override=5 nouveau.runpm=0.

    After the restart the desktop worked fine and I could change between the nvidia and intel graphics and could set my brightness.

    Also, updating the kernel did not solve the problem for me.

    • 1

  7. None of the previous instructions here didn't worked for me Then I watch this video https://www.youtube.com/watch?v=BO-kKKi_ERM and I find out that whole Rc.local file was missing.

    I created a new file:

    printf '%s\n' '#!/bin/bash' 'exit 0' | sudo tee -a /etc/rc.local sudo chmod +x /etc/rc.local sudo -i sudo gedit /etc/rc.local

    I removed all and replace new text with these..

    ec#!/bin/sh -e echo 490 > /sys/class/backlight/intel_backlight/brightness exit 0

    Then reboot and it worked

    I have Xubuntu 18 and after this brightness came up a lot, but still it's not in full mode. I can't adjust it with FN + right/left arrow key. It will show up but does not go anywhere. Volume adjust with up an down arrow keys works fine... weird... Xubuntu 18 seems to have bugss..

    • 1

  8. It may be related to the display driver.

    My issue is solved with the following steps. Dell latitude 5590 with intel VGA compatible driver.

    1. Installed ubuntu with nomodeset option
    2. Updated BIOS to 1.2.3
    3. Updated /etc/default/grub.

    replaced 

    GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"

    with 

    GRUB_CMDLINE_LINUX_DEFAULT="i915.alpha_support=1"

    and

    update-grub
    • 0

  9. I had the same isssue and I added video.only_lcd=0 to GRUB_CMDLINE_LINUX_DEFAULT after quiet splash in /etc/default/grub then updated grub with sudo update-grub rebooted then lcd backlight worked. This was done on a dell xps 14 l421x

    • 0

  10. On Xubuntu 18.04 (Ubuntu with xfce desktop) my brightness problem finally solved.

    I opened 'Onboard Settings' under the 'Settings' menu. If your desktop doesn't have one, you can download it from Software Center.

    On the 'Onboard Preferences' window, click the Layout menu, then choose the 'Full Keyboard' (Desktop keyboard with edit and function keys). Click here to view the Onboard Preferences window

    • 0