Comment # 11 on bug 1087261 from Dario Savella

I am sorry, but I think I did not check this thoroughly.
I just noticed the black screen is only on my primary HDMI display. Upon resume
the additional monitor is refreshed and, by changing resolution and forcing a
reset, the primary comes back to life.
KDE has a bug that looses dual monitor setup. I used to run xrandr at startup,
but I recently tried a different solution, setting screens directly in X11.
Perhaps the new fix does not filly work with suspend...