Public bug reported: Steps to reproduce: 1. Successfully connect AOC u2879vf external display by attaching HDMI cable 2. Remove the cable, output switches to the built-in display and external display goes black 3. Reconnect the HDMI cable again
What is expected: The external screen should display the image (as in step 1) What happened instead: The system thinks the display is connected (see the xrandr output), but the external display is still black (no signal). The clumsy workaround is to use Super+P to switch to "built-in display only" and then back to "joint". After that, the external monitor comes back. xrandr outputs: Step 1 Screen 0: minimum 8 x 8, current 3840 x 3240, maximum 32767 x 32767 DP-0 disconnected (normal left inverted right x axis y axis) HDMI-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 60.00*+ 59.94 50.00 29.98 29.97 25.00 23.98 1920x2160 59.99 1920x1080 60.00 59.94 50.00 1680x1050 59.95 1440x900 59.89 1280x1024 75.02 60.02 1280x960 60.00 1280x720 60.00 59.94 50.00 1024x768 75.03 70.07 60.00 800x600 75.00 72.19 60.32 56.25 720x576 50.00 720x480 59.94 640x480 75.00 72.81 59.94 59.93 DP-1 connected 1920x1080+909+2160 (normal left inverted right x axis y axis) 344mm x 193mm 1920x1080 60.03*+ 40.02 DP-2 disconnected (normal left inverted right x axis y axis) Step 2 Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767 DP-0 disconnected (normal left inverted right x axis y axis) HDMI-0 disconnected (normal left inverted right x axis y axis) DP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm 1920x1080 60.03*+ 40.02 DP-2 disconnected (normal left inverted right x axis y axis) Step 3 Screen 0: minimum 8 x 8, current 3840 x 3240, maximum 32767 x 32767 DP-0 disconnected (normal left inverted right x axis y axis) HDMI-0 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 60.00*+ 59.94 50.00 29.98 29.97 25.00 23.98 1920x2160 59.99 1920x1080 60.00 59.94 50.00 1680x1050 59.95 1440x900 59.89 1280x1024 75.02 60.02 1280x960 60.00 1280x720 60.00 59.94 50.00 1024x768 75.03 70.07 60.00 800x600 75.00 72.19 60.32 56.25 720x576 50.00 720x480 59.94 640x480 75.00 72.81 59.94 59.93 DP-1 connected 1920x1080+1097+2160 (normal left inverted right x axis y axis) 344mm x 193mm 1920x1080 60.03*+ 40.02 DP-2 disconnected (normal left inverted right x axis y axis) ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xorg 1:7.7+19ubuntu14 ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30 Uname: Linux 5.4.0-29-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia .proc.driver.nvidia.gpus.0000.01.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:01:00.0' .proc.driver.nvidia.registry: Binary: "" .proc.driver.nvidia.suspend: suspend hibernate resume .proc.driver.nvidia.suspend_depth: default modeset uvm .proc.driver.nvidia.version: NVRM version: NVIDIA UNIX x86_64 Kernel Module 440.64 Fri Feb 21 01:17:26 UTC 2020 GCC version: ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CasperMD5CheckResult: skip CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: None CurrentDesktop: ubuntu:GNOME Date: Fri May 15 17:43:16 2020 DistUpgraded: Fresh install DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: NVIDIA Corporation TU117GLM [Quadro T2000 Mobile / Max-Q] [10de:1fb8] (rev a1) (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company TU117GLM [Quadro T2000 Mobile / Max-Q] [103c:8611] InstallationDate: Installed on 2020-05-11 (3 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) MachineType: HP HP ZBook 15 G6 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-29-generic root=UUID=9895584a-6648-494d-9d91-e64ba192dd95 ro quiet splash vt.handoff=7 SourcePackage: xorg Symptom: display UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/25/2019 dmi.bios.vendor: HP dmi.bios.version: R92 Ver. 01.02.01 dmi.board.name: 860F dmi.board.vendor: HP dmi.board.version: KBC Version 65.23.00 dmi.chassis.type: 10 dmi.chassis.vendor: HP dmi.modalias: dmi:bvnHP:bvrR92Ver.01.02.01:bd09/25/2019:svnHP:pnHPZBook15G6:pvr:rvnHP:rn860F:rvrKBCVersion65.23.00:cvnHP:ct10:cvr: dmi.product.family: 103C_5336AN HP ZBook 15 dmi.product.name: HP ZBook 15 G6 dmi.product.sku: 6CJ09AV dmi.sys.vendor: HP version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.101-2 version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-2ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.4-2ubuntu1 version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1 ** Affects: xorg (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug focal ubuntu -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1878951 Title: External monitor won't reconnect after reattaching HDMI cable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1878951/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp