https://bugs.freedesktop.org/show_bug.cgi?id=42960
--- Comment #47 from reverber 1806whiteguard@gmail.com --- With kernel 3.15 and later I got "diplay not working after suspend" again. But I find out how to work around. I had scrip on shortcut for KDE and this script made display to work. Command of script is "sleep 1; xset dpms force standby".