Created attachment 142919 [details]
Xorg.log with intel+nouveau drivers
I'm getting black output on HDMI-connected display driven by nVidia GeForce GT 525M (GF108M). Mouse cursor is visible on both built-in display and on the external HDMI-connected display. This used to work on Fedora 27. I can see this on Fedora 29, but I can't pinpoint which package update broke it because I haven't checked the external display (a projector) for quite some time. This machine is a Dell XPS 15 L502X with Intel HD3000 integrated graphics and nVidia GeForce GT 525M discrete GPU in Optimus configuration. Here's my xorg.conf snippet:
Identifier "Internal LCD"
DisplaySize 345 195
DisplaySize 16900 9400
Identifier "Internal Graphics"
Option "Monitor-LVDS1" "Internal LCD"
Option "TearFree" "on"
Identifier "Optimus Graphics"
Option "Monitor-HDMI-1-2" "Projector"
Switching both drivers to "modesetting" makes the issue go away. I'm attaching Xorg logs for both configurations.
Created attachment 142920 [details]
Xorg.log with modesetting driver
Do you still get the problem if you use intel as the main driver and modesetting as the "GPU" driver?
Created attachment 142925 [details]
Xorg.log with intel+modesetting drivers
Yes, the same thing happens with intel driver for the integrated GPU and modesetting for the nVidia GPU. Xorg.0.log attached.