I have a Acer Aspire 5755 with Intel video graphic, on Ubuntu 14.04, the combination Fn+←/→(Right/left) arrows can increase/decrease the brightness screen. Works fine on unity and with a grub modification (boot flags
backlight=vendor) the hot key work on any desktop environment.
I make a direct upgrade to 14.10, and the hot key can not work, even with grub modification. But i can chance the screen brightness in System settings → Brightness and Lock.
ls /sys/class/backlight/ intel_backlight
Anyone have a solution?