Hello, I'm running the EFI Firmware update on my Late 2011 15" Macbook Pro right now. After I started the update, the computer restarted (I think) and a gray screen appeared with the mouse pointer, I can move it around on the screen. The screen has stayed like this for more than half an hour, my question is would it be safe to turn it off and restart it now since it doesn't have the progress bar? It is plugged in. How long should the firmware update usually take? Thanks!