OK, I was doing some debugging with Xorg, and thought I had to use the Magic SysRq key to kill it. But when I had pressed Alt-SysRq-R to give the keyboard control from Xorg back to the kernel, it turned out that I not longer needed to do another SysRq because my Xorg magically worked again… 😉 Unfortunately now, everytime I pressed Alt-F4 to close a window, I found myself on tty4… rather poor. So I needed some way to tell Xorg to grab the keyboard again, and there it is: Just open an xterm and execute
sudo kbd_mode -s
At work I’m using the Dell Latidude E5500 notebook, running on Debian testing. Today, I had some issues with Xorg which could not detect my keyboard and mouse, so I tried to do the Magic SysRq tricks (you can read about it at Wikipedia). Unfortunatley, to press SysRq (on F10), I had to use the Fn key, so if I pressed e. g. Alt+Fn+SysRq+U, the U was detected as keypad 4 because of the Fn key. Luckily, it works as intended if you release the Fn key after having pressed Fn+SysRq, so to remount all mounted filesystems in read-only mode, you would actually hold Alt, hold Fn, hold SysRq, release Fn, press U.
Never thought notebook keyboards were so smart 🙂