Steps to reproduce: 1. boot without Xorg 2. start Xorg with startx 3. enable display rotation 4. quit Xorg At this point, the screen shows previous VT contents and some Xorg stderr spam, but no command prompt. Typing commands doesn't seem to work, CTRL+ALT+DEL too. The system still runs and accepts ssh connections. dmesg shows nothing. Switching between X and VTs (CTRL+ALT+Fx) works normally. The GPU is AMD 880G IGP (HD4250).
Please attach your xorg log and dmesg output.
OK, so I checked Xorg log and it's missing the final line indicating clean shutdown. strace revealed that X is aborting for some reason: <... futex resumed> ) = 0 ioctl(12, DRM_IOCTL_GEM_CLOSE, 0x7ffdfee3d4e0) = 0 close(12) = 0 close(11) = 0 munmap(0x7f1fa4a69000, 13890560) = 0 munmap(0x7f1fa5bef000, 2126232) = 0 munmap(0x7f1fa4861000, 2126248) = 0 munmap(0x7f1fa4649000, 2191808) = 0 write(2, "Xorg: ../include/privates.h:122:"..., 89) = 89 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f1fad47c000 rt_sigprocmask(SIG_UNBLOCK, [ABRT], NULL, 8) = 0 tgkill(2858, 2858, SIGABRT) = 0 --- SIGABRT {si_signo=SIGABRT, si_code=SI_TKILL, si_pid=2858, si_uid=1000} --- +++ killed by SIGABRT +++ So much for a kernel bug, I guess.