Ubuntu – Lenovo Legion 5 15IMH05H brightness control problem

20.04backlightbrightnessdriversnvidia

I have a Lenovo Legion 5 15IMH05H with NVIDIA GeForce RTX 2060 6GB GDDR6/Intel Corporation UHD Graphics (rev 05) and an Intel Processor.
After dual booting windows and Ubuntu 20.04 I encountered a few issues with the changing the brightness. The brightness keys or slider don't work on Ubuntu but they have no problem on windows. I managed to change the brightness by installing the brightness controller app but it is not a perfect solution.
I found an intel_backlight folder in /sys/class/backlight and I tried changing the GRUB several times adding acpi_backlight = vendor, none or video after quick splash.
I also tried editing files in /usr/share/X11/xorg.conf.d like for example the 10-nvidia.conf and I tried creating a 20/80-intel.conf but nothing has worked so far.
It is perhaps worth noting that with intel conf solutions, sometimes vertical green lines appear on the background and the fonts become all blurry or missing. I had to use timeshift to return it to normal.
Here are some of the tutorials I have followed with none working:
https://itsfoss.com/fix-brightness-ubuntu-1310/
https://www.debugpoint.com/2016/10/2-ways-fix-laptop-brightness-problem-ubuntu-linux/
Brightness problem Ubuntu 18.04 LTS
If anyone has found another fix for the legion 5 or faced a similar issues please advise.

Best Answer

One method to control screen brightness that was not covered in the articles you linked to is through xrandr. Give this a try.

Open Terminal
Find the name of your display with: `xrandr | grep " connected" | cut -f1 -d " "
Now set the brightness like this: xrandr --output {display} --brightness 0.7

On my Lenovo ThinkPad, this is what I get:

$ xrandr | grep " connected" | cut -f1 -d " "
eDP-1

Then to set the brightness to 70%:

$ xrandr --output eDP-1 --brightness 0.7

Hope this helps.

Related Solutions

Ubuntu – Ubuntu 14.04 brightness problem (Lenovo Z500)

Two years ago I bought this laptop which works pretty well with Linux. When I upgraded to my new distro, Elementary OS Freya, I noticed the problem that backlight was unable to change. I could change it only on grub screen. After trying every guide on the internet I partially solved the issue by downgrading the kernel (and the related Intel graphics driver) to version 3.13. Yesterday I gave another try. It was very lucky :)

Here the solution:

On the grub configuration file /etc/default/grub modify the following line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

by adding this string: acpi_backlight=vendor.

In my case it is:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Update grub by launching:

sudo update-grub

Then create a xorg configuration file like this:

/usr/share/X11/xorg.conf.d/80-backlight.conf

and copy in it this text:

Section "Device"
    Identifier  "Intel Graphics"
    Driver      "intel"
    Option      "AccelMethod"     "sna"
    Option      "Backlight"       "ideapad"
    BusID       "PCI:0:2:0"
EndSection

Save the file, Reboot, Enjoy :-)

This trick could work on other Lenovo Ideapad laptops. I tested on Lenovo Ideapad z500 on Elementary OS Freya and Debian 8 Jessie.

If you have complitely another laptop you can try this way: Modify grub like in the first part of the guide, update grub, reboot, then verify what backlight "drivers" (I don't know what they are) are being listed. Give:

ls /sys/class/backlight/

and if it gives:

backlight_driver1
backlight_driver2
backlight_driver3

Then create the xorg file with one of the drivers in the list:

Section "Device"
    Identifier  "Intel Graphics"
    Driver      "intel"
    Option      "AccelMethod"     "sna"
    Option      "Backlight"       "backlight_driver1"
    BusID       "PCI:0:2:0"
EndSection

And reboot. If it works, enjoy, otherwise modify the file with another one in the list the same way.

Ubuntu – Can’t control screen brightness – ACPI Error – Lenovo Legion Y540

I also have same laptop Lenovo Legion Y540. This is now fixed in new update but you have to switch the BIOS option for graphics from Discrete Graphics to Switchable Graphics.

Also you have to update grub configuration (i.e. edit the file /etc/default/grub and then run sudo update-grub) as follows:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi=linux acpi_backlight=intel"

Confirm that the acpi_backlight=intel it should not be set to vendor. Setting it to vendor stops the working of function-keys.

Best Answer

Related Solutions

Ubuntu – Ubuntu 14.04 brightness problem (Lenovo Z500)

Ubuntu – Can’t control screen brightness – ACPI Error – Lenovo Legion Y540

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