On Ubuntu 14.10 Utopic, using a Samsung Notebook laptop, I can change the brightness correctly and it is remembered upon wake from sleep.
However my problem is that when my laptop is on battery and I plug it into a power source, the brightness returns to full and remains there even when I unplug it!
When I press a brightness key, it then suddenly remembers and then jumps back to what it should be.
How do I get rid of this annoying behaviour?
Note: I am using TLP.