What Upower DBus Signal is Emitted when Screen is Turned On or Off

[Mystilleef]

Hello,

What upower dbus signal do I need to listen to when my
laptop screen is turned on or off by gnome-screensaver or
gnome-power-manager?

I have a buggy radeon driver that displays multicolored
stripped artifacts on my screen when resuming the laptop, or
its screen, from sleep/suspend/hibernate.

The solution I've found so far is to run a script that
resets the screen after a resume operation. Placing the
script in /etc/sleep.d does the trick. However, this doesn't
work when resuming the screen alone from sleep.

When my screen turns on, I want to run a script that
resets the screen. What signal do I need to listen for?

Thanks