Thanks for your prompt answer! I narrowed things down a bit. As I am using i3 wayland is not an option. I tried a live ubuntu 20.04 and could still reproduce the behaviour described. I went on to enable wayland in live session but failed eventually: XDG_SESSION_TYPE still yielded `x11` but in the process I restarted gdm3 -- and things were fixed. Okay, I went back to the os installed (regolith linux which is i3 based on ubuntu) and after restarting lightdm via systemctl, things are working as expected. That's weird.
Regarding your first question: It is HDMI indeed although xrandr claiming otherwise. There is an HDMI port beneath a DP at the rear and the rest of it is USB. Can I somehow convice the live system to run on wayland? The procedure described here: https://askubuntu.com/a/1258280/595512 did not work for me. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1915382 Title: external Monitor shows »No Signal« after dpms sleep Status in xorg-server package in Ubuntu: Incomplete Bug description: My external Monitor connected via HDMI is behaving strange and my educated guess is it is related to dpms. Plugging in the monitor it will show »No Signal« although recognized by `xrandr`. I would have to boot my machine with the monitor plugged in to make it work. When going to standby (screen blanks after lock, then screen goes to standby) the monitor is switched on (LED is going white) and shortly after it will show the no-signal-message. `xrandr` claims the monitor to be existent. Unplugging and replugging does not help. Same happens when logging out to greeter. Strange in so far as when booting up, the greeter is okay with the monitor. When issuing `xset -dpms` the behaviour changes and the monitor will enter sleep and come back as expected when locking the session. Console (tty1-6) is available though at all times. (I generated the bug report with dpms set off accidentally) ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: xorg 1:7.7+19ubuntu14 ProcVersionSignature: Ubuntu 5.4.0-65.73-generic 5.4.78 Uname: Linux 5.4.0-65-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.16 Architecture: amd64 BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' CasperMD5CheckResult: skip CompositorRunning: None CurrentDesktop: Regolith:GNOME-Flashback:GNOME Date: Thu Feb 11 09:51:33 2021 DistUpgraded: Fresh install DistroCodename: focal DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation UHD Graphics [8086:9bc4] (rev 05) (prog-if 00 [VGA controller]) Subsystem: Dell Device [1028:09c3] InstallationDate: Installed on 2021-02-10 (0 days ago) InstallationMedia: Regolith 20.04.0 1.4.1 LTS amd64 (20200511) MachineType: Dell Inc. Precision 7550 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-65-generic root=/dev/mapper/vgregolith-root ro quiet splash vt.handoff=7 SourcePackage: xorg UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/15/2020 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.3.2 dmi.board.name: 090NVT dmi.board.vendor: Dell Inc. dmi.board.version: A01 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.3.2:bd07/15/2020:svnDellInc.:pnPrecision7550:pvr:rvnDellInc.:rn090NVT:rvrA01:cvnDellInc.:ct10:cvr: dmi.product.family: Precision dmi.product.name: Precision 7550 dmi.product.sku: 09C3 dmi.sys.vendor: Dell Inc. version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1 version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.1 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 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1915382/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
