Occasional black display in Joint Display mode

I am running Leap 15.2/Gnome on my desktop with 2 Displays in ‘Join’ mode. One display is VGA and the other HDMI both connected to the same graphic card.

For a while now (since Leap 15.1) I have been experiencing the following phenomenon: after the displays go into lock mode and I log in again to my user, (sometimes) the VGA screen is black. I recover the display by selecting ‘Single Display’ in ‘Devices/Displays’ settings, selecting ‘Apply’ and then cancelling with ‘Revert Settings’.

My primary display is HDMI which is the user login display after lock mode. The screen at first login after booting the system, which I cannot influence (?) is always the VGA monitor.

My suspicion is that the blackout occurs when I leave my mouse on the VGA display before the lock-out takes place , but this may not be a consistent observation.

Does anyone else notice similar behaviour? Can I do anything to stop this happening?

If you need more than presenting complains to a public then provide valuable info about hardware + drivers.

No BIOS setting to define the port to use? In settings you have defined the primary screen?

xrandr --current | grep "connected primary"

Thank you for replying. I’m not sure exactly what is needed, but from the Yast HW info I found

ID_MODEL_FROM_DATABASE=Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM] (Radeon HD 6450 1 GB DDR3)

The VGA Monitor is a Hanns-G and the HDMI monitor an AOC. Any more data needed?

Thanks, Malcolm.
In the display setting the primary screen is the HDMI one (AOC 22"). I get no return response from

xrandr --current | grep "connected primary"

Ok, just look at the output and see which is primary;

xrandr --current

You may select needed monitor as primary (first).
Please specify monitor model.
Use digital connection (possibly DVI) if available.


inxi -Gxxx
glxinfo | grep -i OpenGL

This is returned, but what does it tell me?:\

Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 8192 x 8192 
XWAYLAND1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 480mm x 270mm 
   1920x1080     59.96*+ 
XWAYLAND2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 480mm x 270mm 
   1920x1080     59.96*+ 

Thanks. This should be a bit more informative :wink:

  Device-1: AMD Caicos [Radeon HD 6450/7450/8450 / R5 230 OEM]  
  vendor: PC Partner Limited driver: radeon v: kernel bus ID: 01:00.0  
  chip ID: 1002:6779  
  Display: wayland server: X.Org 1.20.3 compositor: gnome-shell v: 3.34.5  
  driver: ati,radeon unloaded: fbdev,modesetting,vesa resolution:  
  1: 1920x1080~60Hz 2: 1920x1080~60Hz s-dpi: 102  
  renderer: AMD CAICOS (DRM 2.50.0 / 5.3.18-lp152.63-default LLVM 9.0.1)  
  v: 3.3 Mesa 19.3.4 compat-v: 3.1 direct render: Yes  

OpenGL vendor string: X.Org 
OpenGL renderer string: AMD CAICOS (DRM 2.50.0 / 5.3.18-lp152.63-default, LLVM 9.0.1) 
OpenGL core profile version string: 3.3 (Core Profile) Mesa 19.3.4 
OpenGL core profile shading language version string: 3.30 
OpenGL core profile context flags: (none) 
OpenGL core profile profile mask: core profile 
OpenGL core profile extensions: 
OpenGL version string: 3.1 Mesa 19.3.4 
OpenGL shading language version string: 1.40 
OpenGL context flags: (none) 
OpenGL extensions: 
OpenGL ES profile version string: OpenGL ES 3.1 Mesa 19.3.4 
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10 
OpenGL ES profile extensions: 

Ahh Wayland… could be a Wayland issue, I run Xorg here… if you log out and select the cog, is Xorg an option? If so login into Xorg version and see if it duplicates.

More exactly - XWayland.

Display: wayland server: X.Org 1.20.3 compositor: gnome-shell v: 3.34.5

I have doubts about using Wayland and old videocard with old Mesa 19.3.4.

Yes, I was using ‘Gnome Classic’ and have now switched to ‘Gnome on Xorg’. Let’s see if the phenomenon turns up again. By the way, (under Wayland) after switching the primary display to the VGA (HANNS-G) monitor the other monitor went black after lock-out.

Might try the Modesetting[1] (upstream default, newer technology) DDX driver:

# inxi -GISay
  Host: ga970 Kernel: 5.3.18-lp152.44-default x86_64 bits: 64 compiler: gcc v: 10.2.1...
  Desktop: KDE Plasma 5.18.5 tk: Qt 5.12.7 wm: kwin_x11 dm: TDM
  Distro: **openSUSE Leap 15.2**
  **Device**-1: AMD Cedar **Radeon HD** 5000/6000/7350/8350 Series]
  vendor: PC Partner Limited **driver: radeon** v: kernel bus ID: 01:00.0
  chip ID: 1002:68f9 class ID: 0300
  **Display: server: X.Org 1.20.3 compositor: kwin_x11 driver: loaded: modesetting**
  unloaded: fbdev,vesa alternate: ati display ID: :0
  screens: 1
  **Screen-1: 0 s-res: 1920x2250** s-dpi: 120 s-size: 406x476mm (16.0x18.7")
  s-diag: 626mm (24.6")
  Monitor-1: HDMI-1 res: 1920x1200 hz: 60 dpi: 94 size: 519x324mm (20.4x12.8")
  diag: 612mm (24.1")
  Monitor-2: VGA-1 res: 1680x1050 hz: 60 dpi: 90 size: 474x296mm (18.7x11.7")
  diag: 559mm (22")
  renderer: AMD CEDAR (DRM 2.50.0 / 5.3.18-lp152.44-default LLVM 9.0.1)
  v: 3.3 Mesa 19.3.4 compat-v: 3.1 direct render: Yes
Info:...Shell: Bash v: 4.4.23 running in: konsole **inxi: 3.3.01**
# xrandr | egrep 'onnect|creen|\*' | grep -v disconn | sort -r
VGA-1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
Screen 0: minimum 320 x 200, current 1920 x 2250, maximum 8192 x 8192
**HDMI-1 connected primary** 1920x1200+0+1050 (normal left inverted right x axis y axis) 519mm x 324mm
   1920x1200     59.95*+
   1680x1050     59.97*+  74.89    59.95    59.88

[1] More info](https://forums.opensuse.org/showthread.php/541438-AMD-Intel-amp-NVidia-X-graphics-driver-primer).

Switching to Xorg seems to have achieved the purpose. I have not had the black display effect since switching 2 weeks ago. Many thanks for your contributions!

You might want to create a bug report about it? openSUSE:Submitting bug reports - openSUSE