xbacklight: No outputs have backlight property - No /sys/class/backlight folder
Solution 1
That is completely normal. To find the directory for your backlight settings, do this:
sudo find /sys/ -type f -iname '*brightness*'
The output should give you something like this:
/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight/brightness
Now, all you have to do is link it to /sys/class/backlight
. To do that:
sudo ln -s /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight /sys/class/backlight
If you still get the error, then do this:
Create the file xorg.conf
:
sudo nano /etc/X11/xorg.conf
And add these lines:
Section "Device"
Identifier "Card0"
Driver "intel"
Option "Backlight" "NAME OF THE FOLDER"
EndSection
Then, to save the file do: Ctrl + X then Y then Enter.
Also, for the Driver
part check for your configuration, i.e., acpi_video0
or intel_backlight
.
Solution 2
Check your /sys/class/backlight
folder. If you can see an intel_backlight
folder there and still you are getting the above error then creating a /etc/X11/xorg.conf
file with the below configuration should work for you. It worked for me.
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "Backlight" "intel_backlight"
EndSection
Also, remember to logout and login again for the changes to take effect.
Reference: Backlight - ArchWiki
Solution 3
Every step required for xbacklight
control
Follow these steps:
-
$ sudo nano /etc/default/grub
and replace the corresponding line withGRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
$ sudo update-grub
- No joking, make sure that the appropriate drivers are actually installed:
$ sudo apt install xbacklight xorg xserver-xorg-video-intel
- Issuing
$ find /sys -type f -name brightness
should yield something like/sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/brightness
-
$ cd /sys/class
This directory should contain a soft link calledbrightness
to the brightness device discovered in the previous step. Should it be missing, create it:$ sudo ln -s /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight/brightness /sys/class/brightness
-
$ sudo nano /etc/X11/xorg.conf
should read:
Section "Device"
Identifier "Device0"
Driver "intel"
Option "Backlight" "intel_backlight"
EndSection
Section "Monitor"
Identifier "Monitor0"
EndSection
Section "Screen"
Identifier "Screen0"
Monitor "Monitor0"
Device "Device0"
EndSection
- The assignment of the physical
XF86MonBrightnessDown
andXF86MonBrightnessUp
keys is explained here for Xubuntu LTS or XFCE users. - Finally, reboot for these changes to take effect.
Solution 4
I woudn't recommend that way as it starts the old bad maintained Intel driver instead of the modesetting driver.
I created a script instead of using xbacklight:
#!/bin/sh
val=$(cat /sys/class/backlight/intel_backlight/brightness)
if [ "$1" = "+" ] ; then
val=`expr $val + 5`
else
val=`expr $val - 5`
fi
echo $val | sudo tee /sys/class/backlight/intel_backlight/brightness
and added tee to sudoers. That works without side effects caused by the Intel driver.
Related videos on Youtube
Carter Roeser
Updated on September 18, 2022Comments
-
Carter Roeser over 1 year
I installed
xbacklight
, hoping that it would be able to control my brightness. When trying to change brightness, I was told "No outputs have backlight property". After looking around, I found that this has to do with my computer not having a/sys/class/backlight
folder. I know that this is the problem but don't know exactly how to fix it.Not sure if its needed or not but here some system info from inxi:
System: Kernel: 3.16.0-57-generic x86_64 (64 bit, gcc: 4.8.2) Desktop: LXDE (Openbox 3.5.2) Distro: Ubuntu 14.04 trusty Machine: HP EliteBook 8460p CPU: Dual core Intel Core i5-2520M CPU Graphics: Advanced Micro Devices [AMD/ATI] Seymour [Radeon HD 6400M/7400M Series]
Does this have to do with drivers (perhaps Intel/AMD graphics drivers)?
-
mekkanizer about 8 yearsWhat if there is already a folder on that path? How do I undo such a replacing ln -s if it breaks brightness (by now it's at least controllable from keyboard)? I've tried creating
xorg.conf
, added bothintel_backlight
and the long absolute path to the folder. But it didn't work. So should I: 1. Try ln -s cuz it's harmless 2. Try some other driver name (btw how do I know it otherwise part of the path?), or 3. Use not the path but the name of the folder (it would be same toDriver
field so that's why I'm asking)? -
user5193682 over 7 yearsIn my computer if I open the file /sys/class/backlight/intel_backlight/brightness, I will see an integer value inside it. Just changed the value and saved, my screen immediatelly got the correct brightness. But if I try to use the ln command proposed, I dont have exactly the same folder, and if I try to do this with my intel_backlight folder, I get the error: ln: failed to create symbolic link '/sys/class/backlight/brightness': Operation not permitted
-
Nobody over 7 years@user9589 This sounds like a permission issue. You did execute the ln command as root, didn't you? And I think you were supposed to link the folder, not the brightness file inside that folder. Anyway, the solution didn't work for me, but I already had a /sys/class/backlight folder.
-
Nolan Akash about 7 yearsFor the
xorg.conf
, do I write the full path of the folder, or the name "intel_backlight"? -
Yan King Yin about 7 yearsOne reason for "operation not permitted" may be that the file name contains characters that should be escaped. That was the case for me.
-
Mephisto over 6 years@YanKingYin How did you do that exactly?
-
Spark_TheCat almost 6 years/sys/class/backlight/intel_backlight the easyer way is just to tell the kernel that it is using the intel-backlight instead of whatever it is expecting
-
johny why over 5 yearsThis did not find my backlight location. This did:
ll /sys/class/backlight/
-
Serge Stroobandt over 5 yearsThis answer is the most straightforward for
intel_backlight
users. -
Timo over 5 yearsIs this file also correct, I assume I do not have
intel
:/sys/devices/pci0000:00/0000:00:02.0/backlight/acpi_video0/brightness
. I also have a fileactual_brightness
inacpi_video0
, both have a 0 integer as content. -
Philip Rego over 4 yearsWhich one is it? There's so many in sys
-
davidchoo12 about 4 yearslogout and login didn't work for me, i had to reboot
-
lindhe almost 4 yearsName of what folder?
-
gallais almost 4 yearsHad to reboot too. This made
xbacklight
work but broke my brightness function keys in the process. For some reason xfce needed me to toggle a switch after that change: wiki.archlinux.org/index.php/… -
mbkfa93 over 3 yearsdoes it harm, or have any side effects to run sudo chmod a+rwx /sys/class/backlight/intel_backlight/brightness and use your script with 'tee' instead of 'sudo tee'
-
Romuald Brunet over 3 yearsFor some reason, this totally breaks hardware acceleration on a secondary monitor, had to revert
-
Sabito 錆兎 stands with Ukraine about 3 yearsFor step 5 I keep getting
ln: failed to create symbolic link '/sys/class/brightness': Operation not permitted
-
int_ua over 2 yearsShouldn't it be a file in
/usr/share/X11/xorg.conf.d
on20.04
+? Tried putting it there and SDDM stopped starting :/