My notebook’s brightness level was always set to maximum notwithstanding my previous adjustments using the brightness slider in the Gnome system menu.
This is a problem experienced by many people on various distributions. Therefore search engine results are helpful to find a solution. Arch Wiki was again the most informative guide that I read during my search. I’ll note here how I solved this issue for future reference.
I confirmed by changing the value written in it that the actual brightness value on my debian 8.3 (debian jessie) system is stored in this file:
/sys/class/backlight/intel_backlight/brightness
This path may be different if your graphics card is different. It would be prudent to check that directory first and use the correct path below accordingly.
If I add the following line to the /etc/rc.local file (before the last line which is “exit 0”) it runs during boot process and set brightness level to the value specified:
echo 75 > /sys/class/backlight/intel_backlight/brightness
Here the value “75” may be increased or decreased according to your preference.
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