There seems to be a problem with the kernel 5.12 and X.org.
When I try to login to i3 with this kernel I get thrown back to tty1.
The last messages read
xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
LX: Suspending AIGLX clients for VT switch(EE) Server terminated with error (1). Closing log file.y/.local/share/xorg/Xorg.0.log" for additional information.(EE) (II) AIGnextcloud: Fatal IO error 11 (Resursen tillfälligt otillgänglig) on X server :0.
clipit: Fatal IO error 11 (Resursen tillfälligt otillgänglig) on X server :0.
i3: Cannot open display
xinit: connection to X server lost
When I boot with kernel 5.11 or 5.10, no such problem occurs.
And I can start wayland (in my case sway) without any problem after booting kernel 5.12. In fact I’m writing this in such a session.
EDIT: Sorry, forgot about the swedish in the error-message. It means Resources not available right now.