After some more research I found out that this is actually due to an unimpelmented feature in Nvidia's drivers.
On this model of laptop, the video output ports all connect directly to the discrete Nvidia GPU, and Nvidia's drivers do not yet support the GPU being used as a sink from the integrated GPU and piping the integrated GPU's output to a display. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to nvidia-graphics-drivers-435 in Ubuntu. https://bugs.launchpad.net/bugs/1849214 Title: "nvidia on-demand" mode does not support external displays Status in nvidia-graphics-drivers package in Ubuntu: Confirmed Status in nvidia-graphics-drivers-435 package in Ubuntu: Confirmed Bug description: In a recent driver, Nvidia finally added Linux support for render offload, where most graphics are rendered on the CPU-onboard GPU and only certain applications are rendered on the discrete Nvidia GPU. I know that Ubuntu 19.10 started shipping some updated Xorg packages to support this. For the most part the mode seems to work great. On my laptop, however, I have found that the "on demand" mode does not detect external monitors (and the monitor says it is not receiving a signal). Switching to "Nvidia" mode, where everything is rendered on the discrete GPU, makes the external displays work. The laptop is a Lenovo Thinkpad X1 Extreme (Gen 1). I have found this occurs both with nvidia-graphics-drivers-435 and nvidia-graphics-drivers-440 in the "graphics-drivers" ppa. ProblemType: Bug DistroRelease: Ubuntu 19.10 Package: nvidia-driver-435 435.21-0ubuntu2 ProcVersionSignature: Ubuntu 5.3.0-19.20-generic 5.3.1 Uname: Linux 5.3.0-19-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu8 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Mon Oct 21 13:17:38 2019 InstallationDate: Installed on 2019-09-04 (47 days ago) InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416) ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: nvidia-graphics-drivers-435 UpgradeStatus: Upgraded to eoan on 2019-10-21 (0 days ago) --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu8 Architecture: amd64 DistroRelease: Ubuntu 19.10 InstallationDate: Installed on 2019-09-04 (47 days ago) InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416) NonfreeKernelModules: nvidia_modeset nvidia Package: nvidia-driver-435 435.21-0ubuntu2 PackageArchitecture: amd64 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcVersionSignature: Ubuntu 5.3.0-19.20-generic 5.3.1 Tags: eoan third-party-packages Uname: Linux 5.3.0-19-generic x86_64 UpgradeStatus: Upgraded to eoan on 2019-10-21 (0 days ago) UserGroups: _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/1849214/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
