Test on Intel Tiger Lake platform with nvidia dGPU (N17S-G5 PCI\VEN_10DE&DEV_1C94).
Distribution: Ubuntu Codename: focal kernel: 5.6.0-1018-oem NV driver: 440.100 nvidia_drm modeset=1 gdm3: 3.34.1-1ubuntu1 xserver-xorg-core: 2:1.20.8-2ubuntu2.1 The device can detect external 4K/UHD monitor sucessfully by HDMI or DP. It seems the original issue is not able to reproduce on this machine. However, the modeset has to be enabled for https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-390/+bug/1769857/comments/5, but it is disabled by default currently. ** Attachment added: "Attach my external monitors edid for reference" https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1716857/+attachment/5392513/+files/philips-edid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd 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 Status in gdm3 package in Ubuntu: Opinion Status in nvidia-graphics-drivers-375 package in Ubuntu: Confirmed Status in nvidia-graphics-drivers-418 package in Ubuntu: Confirmed Status in nvidia-graphics-drivers-430 package in Ubuntu: Confirmed Status in nvidia-graphics-drivers-435 package in Ubuntu: Confirmed Status in systemd package in Ubuntu: Confirmed Bug description: Context: 17.10 development packages, nvidia binary driver 375, modeset=1 for the nvidia driver. ubuntu desktop (gnome shell), fresh install ThinkPad W520 in Nvidia Optimus bios mode. Nvidia profile. Result: no external monitors are detected. xrandr does not even list them as disconnected (normally it would list five external disconnected monitors) lsmod shows that nvidia driver is loaded and the modesetting is working at some level because there is no tearing on the laptop panel Note: modeset=1 is the only way to get flicker-free graphics on the laptop panel. modeset=1 is not the default setting but it is highly desirable. It works if lightdm is used which is why I have reported this against gdm3 My sessions in this configuration have mostly crashed after a few minutes with a gdm3 fail whale message in syslog but nothing else looks interesting. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1716857/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp