I have a problem of too slow brightness change when I use the resp. keys on my keyboard.
When I push one of the keys just shortly it takes about a second for the brightness to decrease/increase. Pressing the key for a long time, in order to set the brightness to the lowest level, takes several seconds. And it takes even more time to increase the brightness since it still tries to decrease the brightness even when it's on the minimum level.
After that I cannot change the brightness for more than 10-15 seconds (depending on how long I pressed the button the first time).
My laptop is an HP Pavilion 15 n292-sr.