I'm experiencing this too, using Ubuntu 13.10 on Dell E6530 laptop. After pressing Fn+up/down, nothing happens for 1-2s, then the brightness is changed, then the OSD for it pops up. I can only change the backlight in steps with this frequency.
During that waiting, the whole system (terminals, mouse, keyboard, ...) becomes sluggish, CPU meter does *not* go up. I don't remember to change anything related since the install. The backlight stepping works find on the older Dell V13 laptop using Ubuntu 13.04 (though it had its own problems in the past -- one direction keypress behind). -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-power-manager in Ubuntu. https://bugs.launchpad.net/bugs/847001 Title: Adjusting display brightness is very slow on several Dell laptops To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/847001/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
