# I have fedora22 installed on a Zoostorm tablet but the screen backlight control works in reverse

The brightness slider on the dropdown works in reverse, i.e. moving the slider to the right reduces brightness, to the left increases it. If it is on battery power and is set to reduce brightness after a period idle then it increases to full brightness after the elapsed time. Not much good for saving battery power!

Using  xrandr --output eDP1 --brightness X to change the backlight works correctly, i.e. a higher value gives greater brightness.

Using  xbacklight  returns a low value when the control is to the left and a high value to the right, as expected, but xbacklight = 90 produces a lower brightness than xbacklight = 10 . Similarly incrementing xbacklight reduces brightness, whereas decrementing it increases brightness.

In other words, although xbacklight reads the brightness level correctly, it sets it incorrectly.

It looks like a problem with the display manager, but I don't know enough about Fedora to fix it.

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