Unable to set brightness Acer Switch 10 Tablet Intel Baytrail

I can see the following:

ls /sys/class/backlight/intel_backlight/ actual_brightness brightness max_brightness scale type bl_power device power subsystem uevent

If I try to echo a new value into the brightness file it doesnt change the brightness.

I am running the latest updated version of Fedora.

where you root when you did that?
got to be root or sudo to echo new value into file to get it to change.
one of mine .. find out what max is then use that or lesser number to set brightness .. of course you will need to use your dir path to your system.

echo $(cat /sys/class/backlight/radeon_bl0/max_brightness)
sudo su -c ' echo 200 >  /sys/class/backlight/radeon_bl0/brightness'

Thanks for your help.

I did do it as root in my case I have intel_backlight. I can change the value in the brightness file but it doesnt change my screen brightness.

Originally Posted by jimdaworm Thanks for your help. I did do it as root in my case I have intel_backlight. I can change the value in the brightness file but it doesn't change my screen brightness.

poke around in that parent dir and look for others that might work.
for instance my backlight dir had a link to this.

$ ls -ls /sys/class/backlight/intel_backlight
0 lrwxrwxrwx 1 root root 0 Feb 23 13:55 /sys/class/backlight/intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight

I do remember on that example I gave you was for a old laptop, and I had to poke round and figure out which dir I needed to go into the find the right files to mod to get the backlight to work. it seems you should try the same.

$ find  /sys/devices/ -type d -name drm
/sys/devices/pci0000:00/0000:00:02.0/drm

plus it is a tablet. So I have no idea. what desktop you using, like xfce4, mint, cinnamon, and a few others should all have a little applet to control the brightness you can use too.