You are not logged in.
I'm using a Studio 1555 and changing the brightness via the dedicated keys causes the screen to severely flicker for a while and for gnome-shell to be unresponsive until it stops.
I've attached a video of the problem. I've also tried editing grub.cfg and adding noapic but that did not work.
Warning, you might want to disable audio as I just recorded this at work. Sorry for the reflection.
Offline