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mind5t0rm

Member

Registered: 2021-04-29

Posts: 5

"No outputs have backlight property" xbacklight error

Dear forum members

I'm struggling with this section of the wiki:
https://wiki.archlinux.org/title/Backlight#xbacklight

I'm trying to make the brightness increase/decrease buttons to work

The wiki says:

If you get the "No outputs have backlight property" error, it is because xrandr/xbacklight does not choose the right directory in /sys/class/backlight. You can specify the directory by setting the Backlight option of the device section in /etc/X11/xorg.conf.d/20-video.conf

And goes on to suggest an example for Intel graphic drivers.

I'm NOT using any 3rd party graphic driver, but the default Xorg graphic driver.

How should I configure the /etc/X11/xorg.conf.d/20-video.conf in order to work correctly?

At the moment, I haven't yet created this file because I'm not sure about the details of the Xorg Graphic Driver.

Wiki example:

Section "Device"
    Identifier  "Intel Graphics" 
    Driver      "intel"
    Option      "Backlight"  "intel_backlight"
EndSection

Thank you very much for your help

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,991

Re: "No outputs have backlight property" xbacklight error

You should simply not use xbacklight but any of the other alternatives that are more intelligent in what they do. xbacklight explicitly relies on a functionality of xf86-video-intel that isn't replicated in any other driver, but there's no technical reason for this dependency to exist. acpilight provides ab xbacklight drop in binary while being able to directly adjust the relevant backlight control file regardless of the xorg driver in use.

Also is this still an ALARM system? You really need to ask on the ALARM boards, there are always potential differences here that we are unable to cover here.

Last edited by V1del (2021-05-15 14:22:30)

mind5t0rm

Member

Registered: 2021-04-29

Posts: 5

Re: "No outputs have backlight property" xbacklight error

Thank you very much

I was not aware of that and will replace it with acpilight as suggested and report back

However, I'm not sure i understand your second question about the ALARM system (newbie here)

mind5t0rm

Member

Registered: 2021-04-29

Posts: 5

Re: "No outputs have backlight property" xbacklight error

You should simply not use xbacklight but any of the other alternatives that are more intelligent in what they do. xbacklight explicitly relies on a functionality of xf86-video-intel that isn't replicated in any other driver, but there's no technical reason for this dependency to exist. acpilight provides ab xbacklight drop in binary while being able to directly adjust the relevant backlight control file regardless of the xorg driver in use.

Did that already and now the command (example) is working succesfully

xbacklight -set 50

Now using xbindkeys trying to map this to my brightness functions keys.

Any advises?

Thank you very much

Last edited by mind5t0rm (2021-05-19 13:45:05)