[e-users] new laptop setup -> screen flickers three times

[Peter K. <pe...@as...>]

Hi!

I am installing a fresh new laptop with a NVIDIA GTX1060 graphics card, using debian 9.

I have freshly compiled and installed efl 1.19.0 and enlightenment 0.21.7 yesterday, so far so good.
Now I have connected two external monitors to that, one via display port to the left, another via HDMI to the right, and that works too.
The laptop screen showed some color steps in the background gradient, which vanished after setiing the Dithering Controls in the NVIDIA X Server Settings application to Enabled - Temporal - Auto.
At that point somewhere I opened the enlightenment Settings panel, Screen -> Screen Setup, which gives another configuratino view on the setup.
Here I activated "Laptop Lid" and "Backlight" for the laptop display (some tooltip or help text explaining whast this actually does would not hurt, either..). Clicking on "Apply", I noticed that the laptop display backlight(or the screen from black to gray?) flickers three times before showing the normal screen again.

The same thing happens on entering the session after login. This is independent of the options checked in the settings panel.
I can stop this behaviour by deselecting "Restore setup on start" in this panel and logout/login or restart, but then strangely the color
stepping on the display reappear. Now I am not sure how all these configuration mechanisms play together, but I would like to avoid inducing
some hardware damage by this strange flickering. There does not seem to be any error being logged, so it is probably just some autoadjustment of screen size or something, but I never had this on any other laptop before.

There also still is the preinstalled ubuntu 17.04 running a gnome3 environment on the machine, and there everything looks fine, so it is not a hardware problem...

Switching off one of the external monitors produces five flickers, each coming in maybe half a second from each other, switching it on again gives seven flickers, all only on the laptop display. It looks a bit as if some modes are probed and fail or something similar.

Any ideas what that might be and how to avoid it?

regards
   Peter