I have followed many instructions in the past and now things are bad. Like: Suppose if I sleep and wake up my laptop, I have to toggle the brightness again in order to make my PC realize what was my brightness level.

This happens also when I restart or start my laptop.

The weird thing is there is certain brightness level, let's say its 50% showing up in brightness panel but until and unless I don't toggle it, PC doesn't respond to that amount of brightness.

I use Ubuntu 19.04.


I have uninstalled xbacklight. Things are fine now.

In the past, after upgrading my OS from Ubuntu 18.10 to 19.04, I had to install xbacklight in order to make my brightness button working. My guess is, later Ubuntu update fixed this, so I don't need xbacklight anymore.

If u want to keep xbacklight and have this issue, you can try this solution:

Go to /etc/default/ directory and edit "grub" file with "sudo" privilege. and edit try adding below words in this line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash":

"acpi_backlight= native"



Note: above line is written after "splash " word. Use 1 line at a time. See if it resolve the issue by rebooting the pc. Keep the changes if the one (i.e native, video, none) that is working.

If removing "acpi_backlight", works fines, u might don't need xbacklight anymore. Which is what I did.

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