Disable touchscreen area (root available) My rooted Xperia Z1 on Android 5.1 has a broken touchscreen area in the upper half of the screen.

I was able to partly solve the problem by following this SO question:
Resize screen for Dead touch zone

My problem is: The broken area constantly sends touch events. By that, I am not able to input any touch events myself.

How can I filter any touch events in the upper half of my screen?
you can use wm size (WIDTH)x(HEIGHT)
the difference between size and overscan is that any input outside the screen area will be ignored if you use size to change the display resolution

first you have to know the resolution and the display density of the device. In the terminal/cmd enter adb shell dumpsys display | grep mBaseDisplayInfo to show display related info. 
in my case it's 


real 1080x1920
density 480


the equivalence for wm overscan 0,0,a,b is wm size (WIDTH-a)x(HEIGHT-b). In my case wm overscan 0,0,30,0 --> wm size 1050x1920