After update to 18.04 from 17.10, my second monitor seems to be detected (though weirdly as " Samsung Electric Company 19" " when it actually is Samsung SyncMaster 940N) but is black. It is set to join displays and I can blindly manipulate stuff on the second display desktop space.
I have vanilla Gnome installed though switching to Ubuntu styled Gnome changes nothing. Forcing no wayland also doesn't seem to do anything.
What can be the problem?
Edit:
Result of lspci -nnk | grep -A3 -Fe '[0300]'
:
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Tonga XT / Amethyst XT [Radeon R9 380X / R9 M295X] [1002:6938] (rev f1)
Subsystem: Gigabyte Technology Co., Ltd Radeon R9 380X [1458:22c8]
Kernel driver in use: amdgpu
Kernel modules: amdgpu
Result of xrandr
using single display mode:
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
HDMI-A-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 598mm x 336mm
1920x1080 60.00*+ 50.00 59.94
1680x1050 59.88
1600x900 60.00
1280x1024 60.02
1440x900 60.00
1280x960 60.00
1280x800 59.91
1280x720 60.00 50.00 59.94
1024x768 60.00
1024x576 59.97
800x600 60.32
720x576 50.00
720x480 60.00 59.94
640x480 60.00 59.94
DVI-D-0 disconnected (normal left inverted right x axis y axis)
DVI-D-1 connected (normal left inverted right x axis y axis)
1280x1024 60.02 + 75.02
1280x960 60.00
1280x800 60.02
1152x864 75.00
1280x720 60.02
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 59.94
720x400 70.08
Result of xrandr
using mirror display mode:
Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
HDMI-A-0 connected primary 1280x1024+0+0 (normal left inverted right x
axis y axis) 598mm x 336mm
1920x1080 60.00 + 50.00 59.94
1680x1050 59.88
1600x900 60.00
1280x1024 60.02*
1440x900 60.00
1280x960 60.00
1280x800 59.91
1280x720 60.00 50.00 59.94
1024x768 60.00
1024x576 59.97
800x600 60.32
720x576 50.00
720x480 60.00 59.94
640x480 60.00 59.94
DVI-D-0 disconnected (normal left inverted right x axis y axis)
DVI-D-1 connected 1280x1024+0+0 (normal left inverted right x axis y
axis) 376mm x 301mm
1280x1024 60.02*+ 75.02
1280x960 60.00
1280x800 60.02
1152x864 75.00
1280x720 60.02
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 59.94
720x400 70.08
Edit:
I poked around, reinstalled gnome, made sure I have latest open amd drivers: https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers, searched for the same problems but couldn't find any. It continues to work flawlessly on Win10. What 17.10->18.04 update could've done to make secondary screen black?
Edit:
Tried Live USB and live environment has the same problem, so it seems like there is something incompatible with 18.04.