Every time my laptop screen goes blank or the system goes into suspend in Zorin 17.3 Lite due to inactivity and then turns back on, the screen brightness is set to maximum, even though I had manually set it to minimum beforehand.
How can I fix this without writing a script so that my screen brightness settings
are kept until next reboot?
Is this due to a setting? I hadn't noticed it before, but I'm not sure if it is a new issue. Maybe I accidentally changed something. It happens with different 6.8 kernels, also with 5.15.
I had enabled the xfce4 screensaver and the display power management.
I noticed:
When I turn off the display power management and only keep the xfce4 screensaver enabled, the screen brightness isn't reset after the screensaver had turned on.
When I turn off the xfce4 screensaver and only keep the display power management enabled, the screen brightness isn't reset after screen blanking, too.
After suspend, the screen brightness is sometimes reset to maximum, sometimes not. I haven't figured out yet, why. Maybe it depends how long it stayed in suspend or if the computer went manually into suspend or automatically.
But it is much better now when only one screen saving function is turned on.
Run: xfce4-display-settings --help to see current settings
try resetting Power Manager by removing its config: rm -rf ~/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-power-manager.xml (then restart your session)
I've tried it now by renaming the file, but it didn't help with the brightness. I'll try to find a script which saves the current brightness value before suspend and restores the same value after suspend.
Perhaps it also would help to reduce the value in the file "brightness" at /sys/class/backlight/. At the moment it is set to maximum.
But the best would be when during a session the settings which are made with the keyboard keys after login to set the brightness, are kept until shutdown or until I want to change them - but not automatically are reset.
Hello,
I asked Leo, Brave’s AI, and he listed some information, maybe it’ll help
For Zorin OS 17 Lite using the XFCE4 desktop environment, screen brightness issues after the screen saver or sleep mode are typically resolved by installing or configuring the XFCE Power Manager.
Install Power Manager : Open a terminal and run
sudo apt install xfce4-power-manager
to ensure the necessary tools are present.
Configure Settings : Open the XFCE Power Manager application, navigate to the General or Display tab, and adjust the slider to set the desired brightness level for both battery and plugged-in states.
Verify Functionality : The brightness control should now persist after waking from sleep or the screen saver. If the slider is grayed out, check the ConsoleKit or UPower service status, as these are required for hardware-level brightness control.
Alternative Tool : If the native manager fails, users have successfully used Brightness Controller
The xfce4 -power-manager is already installed, but I'll take a look at the other app and test it in a live session.
Thanks to all who have tried to help me!
I can regulate the brightness with the brightness function keys of the keyboard or the slider in the panel, but the setting which I make there is often reset.
Today I'm too tired because of the heat to try the suggestions.
I tested the brightnesscontroller in a live session, but it didn't help to solve the problem with the brightness after suspend.
I also tested xscreensaver, but the same there.
When I add the command "sudo brightnessctl set ..." (e.g. 8) to the autostart programs, it helps e.g. to have a low brightness after suspend, but then it is always the same value of the brightness and not the last set one.
I saw a script which writes the current value into a /tmp file before suspend, recalls it after suspend to write the brightness value into /sys/class/backlight and then removes the created /tmp file, but that sounds as producing many writing processes.
I've read in the arch wiki that restoring screen brightness can sometimes fail, especially on laptops with optimus graphics cards. Maybe I have such one. But I use nouveau, and at /sys/class/backlight is only shown a folder intel_backlight and no other one.
Do you have to create separate custom entries for each trigger situation, e.g., for login, suspend, etc., or can you enter multiple triggers in a single custom autostart entry in the RunHook line?
I just tested it. It doesn't reliably restore the screen brightness to what it was before the system went into suspend mode. Sometimes it works, sometimes it doesn't.
In the linked guide was a link to a ppa with a script, but it is not for ubuntu 22.04 and very old.
In a live session of Zorin 18.1 Core with Zorin Lite desktop, I don't have the problem as in Zorin 17 Lite (with disabled xfce screensaver). In a Zorin 17 Lite live session yesterday, I had the same issue as on my bare metal system.
On Zorin 18.1 Lite desktop, the screen brightness is never reset during a session.
Can I make the same configuration in Zorin 17 as in Zorin 18? What's different here? Which files matter?
Edit:
Now I installed on my bare-metal Zorin 17 Lite system the liquorix kernel to test it with a later kernel, and guess what: With liquorix it works! No problem with the screen brightness there.
Does anyone have some more ideas on how I can make it work with the default 6.8 kernel? Next, I'm going to try some kernel parameters as e.g. acpi_backlight=vendor or native.
I also wanted to save the original folder which /sys/class/backlight/intel_backlight is linked to from Zorin 18 live session on my internal Zorin 17 drive to test it with that file, but there were copy errors shown with a suspend file.
When the Liquorix Kernel works, it contains maybe a Driver or Firmware what supports Your specific Brightness Control better that the default Kernel or in the default one is the Driver or whatever supports it not included or only in a Version that doesn't work well. That would be at least my Guess.
It iseems to be not a kernel problem, but a XFCE desktop problem, because on Zorin 17 Core with kernel 6.8, the screen brightness isn't reset on my system.
I haven't figured out, why, although I've made some tests with the removal of xfce4-screensaver.
I mean the Screensaver gives You a blank Screen for saving the Screen for Burn-in's. But the Power Management makes the Screen blank with turning it off to save Power. Maybe the one Action doesn't like the other.
I tried it with the kernel parameter acpi_backlight=vendor today, and it worked and solved the problem (with kernel 6.8). The screen brightness is no longer reset to maximum.
The xfce4 screensaver already was disabled and removed from autostart to avoid conflicts. In my other thread, I showed the default setting for my question, because I was wondering if the two instances for screen blanking may cause conflicts.
But even with the xfce4 screensaver disabled, I had still problems.
