I am unable to reduce Laptop brightness in Ubuntu 20.04 after upgrading.
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Installed brightness-controller to adjust brightness but still unable to adjust the brightness.
sudo add-apt-repository ppa:apandada1/brightness-controller
sudo apt update
sudo apt install brightness-controller -
Tried to solve issue by enabling Laptop Specific Drivers by adding below line in /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
But still unable reduce brightness.
sudo lspci|grep VGA
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (Whiskey Lake) (rev 02)
sudo lshw -c video
*-display UNCLAIMED
description: VGA compatible controller
product: UHD Graphics 620 (Whiskey Lake)
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 02
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm vga_controller bus_master cap_list
configuration: latency=0
resources: memory:c0000000-c0ffffff memory:b0000000-bfffffff ioport:4000(size=64) memory:c0000-dffff
Best Answer
I had the same problem as you and the only solution that worked for me was to upgrade the kernel as per the procedure is described in this video: https://www.youtube.com/watch?v=PgRgUe3eWj0. However, I will post the steps here in case the link goes offline. However, this should be a last resort in case nothing else works. Make sure Secure Boot is turned off in the BIOS. Make a backup of your data before this.
Step 1: Add Cappelikan PPA
To do this, fire up a terminal and type:
sudo add-apt-repository ppa:cappelikan/ppa
Step 2: Make sure system is up to date and install Mainline
The Cappelikan PPA has Mainline in its repository, which is a reliable application for upgrading the kernel in Ubuntu.
To install Mainline and make sure the system is up to date, type this in the terminal one after another:
sudo apt update
sudo apt install mainline
Step 3: Upgrade kernel
Open up Mainline through the application menu. It should appear as 'Ubuntu Mainline Kernel Installer' (you may not see the full name, it might appear as 'Ubuntu Main...' or something along those lines)
Wait for the application to load, and it should show you a list of kernels to install. I suggest you go with a kernel that is 5.8 or above. Anyway, select a kernel and click 'Install'. The process will take some time.
Once its done, it'll tell you to close the window and restart.
Reboot and run
uname -r
in the terminal to check your kernel version. If it is the one you selected and installed earlier, you should be good to go and your brightness problem should be fixed.Wish you best of luck. If you any more problems, don't hesitate to ask.