Hi, I am using Raspberry Pi 3 model B, everything works fine, but whenever I write startx, the input devices don't work any more. I can't access TTY, and nothing except sysrq works.
LXDM autostart has the worst effect. It freezes the system, nothing works unless I sysrq and use REISUO or REISUB keys to poweroff/reboot my pi. I have removed the lxdm entry (/etc/systemd/system/display-manager.service) after inserting the SD card into my laptop, because the pi stuck after boot.
No partial upgrades was done. No errors on startx. X.org starts normally, but input devices are not responsive.
There were no problems, but after installing xfce4, and running startxfce4, xfce4 showed libffi.so.7 is missing, so I upgraded my system, and libffi. Now xorg is freezing.