display is detected on a non-connected DP port

[Szilárd Páll]

I have my screen connected to HDMI, and I also have a DP cable plugged in. The single screen attached gets detected twice, xrands shows both HDMI-1 as connected (primary) and DP-1 connected as well. If I disconnect the DP cable xrandr does now show it as connected anymore. xrandr output below:

$ xrandr
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
HDMI-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 553mm x 311mm
   2560x1440 59.95*+
   2048x1152 60.00
   1920x1200 59.95
   1920x1080 60.00 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98
   1920x1080i 60.00 50.00 59.94
   1600x1200 60.00
   1680x1050 59.88
   1280x1024 75.02 60.02
   1200x960 59.99
   1152x864 75.00
   1280x720 60.00 50.00 59.94
   1024x768 75.03 60.00
   800x600 75.00 60.32
   720x576 50.00
   720x576i 50.00
   720x480 60.00 59.94
   720x480i 60.00 59.94
   640x480 75.00 60.00 59.94
   720x400 70.08
DP-1 connected (normal left inverted right x axis y axis)
   2560x1440 59.95 +
   2048x1152 60.00
   1920x1200 59.88
   1920x1080 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98
   1920x1080i 60.00 50.00 59.94
   1600x1200 60.00
   1680x1050 59.95
   1280x1024 75.02 60.02
   1200x960 59.99
   1152x864 75.00
   1280x720 60.00 50.00 59.94
   1024x768 75.03 60.00
   800x600 75.00 60.32
   720x576 50.00
   720x480 60.00 59.94
   640x480 75.00 60.00 59.94
   720x400 70.08
HDMI-2 disconnected (normal left inverted right x axis y axis)

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-xorg (not installed)
ProcVersionSignature: Ubuntu 4.10.0-33.37~16.04.1-generic 4.10.17
Uname: Linux 4.10.0-33-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: Budgie:GNOME
Date: Mon Sep 4 00:45:37 2017
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 5.0.40, 4.10.0-28-generic, x86_64: installed
 virtualbox, 5.0.40, 4.10.0-32-generic, x86_64: installed
 virtualbox, 5.0.40, 4.10.0-33-generic, x86_64: installed
 virtualbox, 5.0.40, 4.4.0-93-generic, x86_64: installed
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Sky Lake Integrated Graphics [8086:1926] (rev 0a) (prog-if 00 [VGA controller])
   Subsystem: Intel Corporation Skylake Integrated Graphics [8086:2063]
InstallationDate: Installed on 2016-06-18 (441 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.10.0-33-generic root=UUID=04f11ff8-1726-4c69-9fec-69890c6d9f74 ro text
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.vendor: Intel Corp.
dmi.board.vendor: Intel corporation
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.76-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 17.0.7-0ubuntu0.16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 17.0.7-0ubuntu0.16.04.1
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A
xserver.bootTime: Mon Sep 4 00:25:20 2017
xserver.configfile: /etc/X11/xorg.conf
xserver.errors:
 Failed to load module "fbdev" (module does not exist, 0)
 Failed to load module "vesa" (module does not exist, 0)
 Failed to load module "fbdev" (module does not exist, 0)
 Failed to load module "vesa" (module does not exist, 0)
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.19.3-1ubuntu1~16.04.2
xserver.video_driver: modeset

[Paul White (paulw2u)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to review all reported bugs in a timely manner.

Ubuntu 16.04 (xenial) reached end-of-standard-support on April 29, 2021.

I'm setting the status of this bug to 'Incomplete' as it's not seen any activity for some time. If this is still an issue when using a currently maintained release of Ubuntu then please let us know which one(s) otherwise this bug report can be left to expire in approximately 60 days time.

[Launchpad Janitor (janitor)]

[Expired for xorg (Ubuntu) because there has been no activity for 60 days.]