maintainer-feedback requested: [Bug 259402] x11-servers/xorg-server: stopping X makes system unresponsive

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-x11 (Nobody)
<x11@FreeBSD.org> for maintainer-feedback:
Bug 259402: x11-servers/xorg-server: stopping X makes system unresponsive
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=259402



--- Description ---
When shutting down a X user session system hangs with black screen not reaching
the shell prompt in tty0. The system is completely inresponsive to keyboard or
mouse events. Black screen with cursor in upper left corner and unmovable
mouse-pointer in the middle.

I now upgraded x11-servers/xorg-server 1.20.11_3,1 -> 1.20.13,1 but the problem
was there for some weeks before, persisting this upgrade.

Searching for solutions I found others having exactly the same problem too:
https://forums.freebsd.org/threads/i-cannot-stop-x.82545/

There I learned that first switching to tty0 and killing X there at least gives
me a terminal prompt again:

(II) AIGLX: Suspending AIGLX clients for VT switch			       

^Cxinit: connection to X server lost					       


waiting for X server to shut down XIO:	fatal IO error 4 (Interrupted system
call) on X server ":0"				   

      after 179932 requests (179929 known processed) with 0 events remaining.  


..........								       


xinit: X server slow to shut down, sending KILL signal			       

									       
					   waiting for server to die	       


xinit: unexpected signal 2						       

-------

No clues in the xorg logfile.
looking at ps aux after shutdown (via ssh from other box) shows no more
X-related processes.