I am running Gentoo system and experienced some situation which can be resolved, but is possible bug. I have installed following kscreen version: [I] kde-plasma/kscreen Available versions: (5) 5.11.5^t (~)5.12.1^t {debug test} Installed versions: 5.12.1(5)^t(09:24:18 02/15/18)(-debug -test) Homepage: https://cgit.kde.org/kscreen.git Description: KDE Plasma screen management Unexpected situation description: 1. I have 2 monitors connected to nvidia 1080 ti both via display port, 43" and 24". 2. Second 24" monitor I configured ?< 90* Counterclockwise and all works - screenshot from systemsetting attached (kde-plasma_system-settings_displays.png) 3. I restart the system 4. After boot, main monitor is OFF and second display is displaying terminal in NON <90* Counterclockwise, but XDM is off, so I understand this. Question: Why is main monitor OFF - not sure if right place to ask for it as XDM is off in that moment. 5. I log in and start manually /etc/init.d/xdm start 6. After start of XDM login screen appear on still NON clockwised secondary monitor - note I use DISPLAYMANAGER="sddm", primary monitor is still OFF Question: I would expect in this moment the monitor should rotate < 90 Counterclockwise as windows system is in control, but not sure. Is SDDM using plasma monitor settings or not? 7. After plasma desktop is loaded main monitor is finally switched ON and displays correctly desktop while the second monitor is reportedly on (have signal from GPU), the screen is black and have following behaviour: A. When I move mouse over the second monitor, the cursor is visible B. When I try to move some window from main monitor to second one, I can see only mouse cursor, but no window of moved application C. The desktop background is not visible, background is simply black 8. After I just try to little bit move alignment in systemsettings-display and do Apply (button) the second monitor remain still in the same kind of state (all previously 3 described behaviours apply) 9. To fix this situation I just switch the second monitor to other orientation and then back to expected < 90* Counterclockwise 10. All is back to expected state Same behaviour after each restart.
Created attachment 110807 [details] Double screen configuration with one <90* oriented
Created attachment 110812 [details] Repair operation Update: The suggested step 9 didn't fix the situation. I still cannot see windows on second screen, but the wallpaper is already visible. But when I move the screen little bit up, the windows are visible. I realized the second monitor must be moved little bit under the bottom line of primary monitor as in attached second screen. If both monitors are aligned at bottom line level, the second screen doesn't show any window.
These symptoms are not controlled by kscreen, they're probably a driver problem or something lower in the graphics stack. I'm afraid I'll have to close this bugreport, since it won't be very useful for us in improving Plasma. You may have more luck reporting this to nvidia or Xorg.
Ok, I see. I also confirm here for anybody experiencing the same that same situation occur when I just logout and login again. On logout I see 2 screens on both displays, but after login back from sddm to plasma desktop the second one is simply dark, and the only thing required to work is just move littlebit alignment in settings and aply and it work again.