Another correction. For the one workaround, switching to discrete graphics in the BIOS only seemed to get past the initial gnome login. But resuming from DPMS off/suspend, the same error loop happens even when hybrid graphics is disabled in the BIOS.
Even worse, seems hardware acceleration ends up being disabled: $ journalctl --no-hostname -b -p warning _COMM=gnome-shell -- Logs begin at Wed 2019-02-06 14:13:52 SAST, end at Sun 2020-05-03 16:09:45 SAST. -- May 03 14:51:40 org.gnome.Shell.desktop[2284]: glamor: 'wl_drm' not supported May 03 14:51:40 org.gnome.Shell.desktop[2284]: Missing Wayland requirements for glamor GBM backend May 03 14:51:40 org.gnome.Shell.desktop[2284]: Failed to initialize glamor, falling back to sw ... May 03 14:53:25 gnome-shell[6549]: setup_framebuffers: assertion 'width > 0' failed The "EGL failed to allocate resources" error stops happening probably because gnome-shell isn't even using hardware acceleration now. I've also disabled all gnome shell extensions to avoid noise/errors in the logs and will try weed out the problem better. I checked `grep -C2 -E '(EE)|(WW)' /var/log/Xorg.0.log` and things seem fine: [ 45.181] (II) NVIDIA dlloader X Driver 440.59 Thu Jan 30 01:08:17 UTC 2020 [ 45.181] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs -- [ 45.182] (II) LoadModule: "ramdac" [ 45.182] (II) Module "ramdac" already built-in [ 45.183] (WW) Falling back to old probe method for modesetting [ 45.183] (II) NVIDIA(0): Creating default Display subsection in Screen section "Default Screen Section" for depth/fbbpp 24/32 -- [ 46.392] (==) NVIDIA(0): Silken mouse enabled [ 46.392] (==) NVIDIA(0): DPMS enabled [ 46.393] (WW) NVIDIA(0): Option "PrimaryGPU" is not used [ 46.393] (II) Loading sub module "dri2" [ 46.393] (II) LoadModule: "dri2" Note, I've done no customisation to X config - trying to stick to defaults. xrandr confirms only one provider / hybrid is indeed off and Intel not in use: $ xrandr --listproviders Providers: number : 1 Provider 0: id: 0x218 cap: 0x1, Source Output crtcs: 4 outputs: 6 associated providers: 0 name:NVIDIA-0 I'm guessing the Lenovo P53 impliments a mux/switch to connect the laptop panel to the NVidia card so that Intel is disabled in this mode. And double checking, also no i915 modules are loaded: $ lsmod | grep '^drm' drm_kms_helper 180224 1 nvidia_drm drm 491520 10 drm_kms_helper,nvidia_drm So there seems to be, on current Ubuntu 18.04.4 LTS (fully up to date as of today), a 4K / UHD 60Hz issue with Nvidia, as seen in X log [ 45.228] (II) NVIDIA GLX Module 440.59 Thu Jan 30 01:05:38 UTC 2020 Lastly, I think due to `needs_root_rights=yes` in /etc/X11/Xwrapper.config, X logs to /var/log/Xorg.0.log again instead of the X without root which used to log at ~/.local/share/xorg/Xorg.0.log -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to nvidia-graphics-drivers-430 in Ubuntu. https://bugs.launchpad.net/bugs/1716857 Title: nvidia-drm.modeset=1, gdm3 and optimus laptop results in no external monitors detected by Xorg To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1716857/+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