I had a really bad lockup of my X server and had to do a Sys Rq + r to release my keyboard from X and get into a console. I was able to kill the process that was locking up my system, and continue my work in my still running X server.
Now whenever I e.g. push Alt + F4 to kill a window, my system switches to the 4th console instead of killing the active window. So it seems that my keyboard still is in released mode.
How do I undo my previous Sys Rq + r command, such that I can continue my work in my running X server?