I am seeing this again on the latest stable release on Ubuntu 20.04 on a Dell Precision with attached displays.
Linux bdp 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux TU117GLM [Quadro T1000 Mobile] nvidia-driver-440 440.100-0ubuntu0.20.04.1 xrandr output: eDP-1-1 connected (normal left inverted right x axis y axis) PRIME Synchronization: 0 DP-1-1 disconnected (normal left inverted right x axis y axis) PRIME Synchronization: 1 DP-1-2 connected primary 2560x1440+0+0 (0x29e) normal (normal left inverted right x axis y axis) 597mm x 336mm PRIME Synchronization: 0 DP-1-3 disconnected (normal left inverted right x axis y axis) PRIME Synchronization: 1 DP-1-1-1 disconnected (normal left inverted right x axis y axis) PRIME Synchronization: 1 DP-1-1-2 disconnected (normal left inverted right x axis y axis) PRIME Synchronization: 1 DP-1-1-3 connected 1080x1920+2560+0 (0x29f) left (normal left inverted right x axis y axis) 527mm x 297mm PRIME Synchronization: 0 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to nvidia-graphics-drivers-390 in Ubuntu. https://bugs.launchpad.net/bugs/1857271 Title: Focal 440.44-0ubuntu1 PRIME Sync not working Status in nvidia-graphics-drivers-390 package in Ubuntu: New Status in nvidia-graphics-drivers-435 package in Ubuntu: Confirmed Status in nvidia-graphics-drivers-440 package in Ubuntu: Confirmed Bug description: Ubuntu 19.04 (Disco) Linux 5.4.6-050406-generic linux-firmware-1.184 mutter-3.32.2+git20190711-2ubuntu1~19.04.1 nvidia-driver-440: Installed: 440.44-0ubuntu1 Candidate: 440.44-0ubuntu1 Version table: *** 440.44-0ubuntu1 500 500 http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status I've noticed screen tearing with the nvidia 440 driver on 5.4.x kernels. Typically, this is resolved by setting the xrandr option 'PRIME Synchronization' to '1', however, doing so with the above combination results in never being enabled. $ xrandr --output eDP-1-1 --set 'PRIME Synchronization' '1' $ xrandr --verbose | grep PRIME PRIME Synchronization: 0 PRIME Synchronization: 1 PRIME Synchronization: 1 PRIME Synchronization: 1 Reverting to Linux 5.0.0-37-generic resolve the issue, so I figured I'd raise it here first, however, it seems like a potential kernel regression issue if the only thing I'm changing is indeed the kernel version. Your input would be appreciated. I tried to figure out how to post a bug on the PPA, however, it seems bug creation is disabled on that PPA, so I ended up here. I've been testing newer kernel versions to get fixes for other problems with my hardware. Due to another package dependency, I'm stuck on disco for some pulseaudio bluetooth codec support, so I've been pushing forward the kernel, firmware and nvidia driver versions to get the other driver fixes. I realise this is not ideal. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-390/+bug/1857271/+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