# [SOLVED] Backlight not adjusting with Fn keys.

## NTwoO

Hi all,

For some strange reason my laptop screen brightness will not adjust using the Fn keys. The laptop in question is a Dell Latitude E6230. The Fn keys show up in xev as XF86MonBrightnessUp and XF86MonBrightnessDown, so the binding is right. In /sys/class/backlight I only have the intel_backlight device. xbacklight does adjust the backlight, so the option to adjust it using a key binding is an option, but it would be better if everything worked according to spec. Does someone know why? I followed the extensive advice on the Intel pages of Arch and Gentoo wiki and the other fora were scoured indefinitely yesterday.Last edited by NTwoO on Sat Oct 15, 2016 8:45 am; edited 1 time in total

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## Roman_Gruber

Its an UEFI issue.

Uefi reports to windows to adjust the screen brightness and windows does something to change something in the firmware of the hardware.

In the old days the screen brightness was hardwired, was in the firmware / bios of the hardware

Blame it on microsoft.

You can use xrandr to adjust the screen brightness as I do. You can make a kernel.org bug report but do not expect any results (took over a year to get only the wifi kill switch fixed for 3 years old gamer notebook)

You may check out a live cd if it works there flawless. If it does duplicate the kernel and userspace

It is a known issue that special keys do not work anymore starting with UEFI bioses. REgardless of brand / model. 

--

the benefit of the new implementation is that the software can give you a nice popup, bells and whistles, to show you the volume and other stuff.

I still remember the old notebooks with hardwired volume knob. Was much much better and easier. And also worked flawless and still does.

My box do not even generate those xfbrightness up and down acpi events

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## NTwoO

I wonder... My BIOS is set to legacy, so no uefi. The keyboard backlight button works. Then I guess the best would be to do something with xmodmap and xbrightness, since they both work.

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## NTwoO

This'll do it in ~/.config/openbox/lxde-rc.xml

```
  <keybind key="XF86MonBrightnessUp">

      <action name="Execute">

          <command>xbacklight +5</command>

      </action>

  </keybind>

  <keybind key="XF86MonBrightnessDown">

      <action name="Execute">

          <command>xbacklight -5</command>

      </action>

  </keybind>

```

Up to the next problem... hibernation. Ah, the joys.

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