Checking in 17.10 PRIME Synchronization can be enabled & works in UbuntuGnome but doesn't in Ubuntu. Main reason is in UbuntuGnome nvidia_drm.modeset can be enabled, in Ubuntu it can't.
ex.'s UbuntuGnome, gdm3 $ sudo cat /sys/module/nvidia_drm/parameters/modeset [sudo] password for doug: Y $ xrandr --verbose Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 eDP-1-1 connected primary 1920x1080+0+0 (0x46) normal (normal left inverted right x axis y axis) 345mm x 194mm Identifier: 0x42 Timestamp: 21140 Subpixel: unknown Gamma: 1.0:1.0:1.0 Brightness: 1.0 Clones: CRTC: 0 CRTCs: 0 1 2 Transform: 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 filter: _MUTTER_PRESENTATION_OUTPUT: 0 EDID: 00ffffffffffff0030e4d90200000000 00150103802313780a15d59e59509826 0e505400000001010101010101010101 0101010101017e3680b070381f403020 350059c2100000190000000000000000 00000000000000000000000000fe004c 4720446973706c61790a2020000000fe 004c503135365746312d544c4232004b PRIME Synchronization: 1 supported: 0, 1 Same machine in Ubuntu sudo cat /sys/module/nvidia_drm/parameters/modeset [sudo] password for doug: N $ xrandr --verbose Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 eDP-1-1 connected primary 1920x1080+0+0 (0x46) normal (normal left inverted right x axis y axis) 345mm x 194mm Identifier: 0x42 Timestamp: 12578 Subpixel: unknown Gamma: 1.0:1.0:1.0 Brightness: 1.0 Clones: CRTC: 0 CRTCs: 0 1 2 Transform: 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 filter: EDID: 00ffffffffffff0030e4d90200000000 00150103802313780a15d59e59509826 0e505400000001010101010101010101 0101010101017e3680b070381f403020 350059c2100000190000000000000000 00000000000000000000000000fe004c 4720446973706c61790a2020000000fe 004c503135365746312d544c4232004b PRIME Synchronization: 0 supported: 0, 1 So until shown otherwise am adding lightdm ** Summary changed: - PRIME synchronization not working with xserver-1.19.x + PRIME synchronization not working with xserver-1.19.x in Ubuntu ** Also affects: lightdm (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1674304 Title: PRIME synchronization not working with xserver-1.19.x in Ubuntu Status in lightdm package in Ubuntu: New Status in nvidia-prime package in Ubuntu: Confirmed Bug description: xserver-1.19.x is being proposed for 17.04, currently available in test ppa https://launchpad.net/~canonical-x/+archive/ubuntu/x-staging FFe - https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1671799 On 2 separate Optimus laptops there is no sign of it actually working, tearing while using nvidia drivers (375.x) is rampart. Testing with both current 4.10.0-13 & previous 4.9.0-11 kernels. Shows this in kern.log so support is enabled Mar 19 08:18:47 doug-Lenovo-IdeaPad-Y510P kernel: [ 1.746443] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). Mar 19 08:18:47 doug-Lenovo-IdeaPad-Y510P kernel: [ 1.746444] [drm] Driver supports precise vblank timestamp But in Xorg.0.log - randr: falling back to unsynchronized pixmap sharing ProblemType: Bug DistroRelease: Ubuntu 17.04 Package: nvidia-prime 0.8.4 ProcVersionSignature: Ubuntu 4.10.0-13.15-generic 4.10.1 Uname: Linux 4.10.0-13-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia ApportVersion: 2.20.4-0ubuntu2 Architecture: amd64 CurrentDesktop: Unity:Unity7 Date: Mon Mar 20 07:53:12 2017 InstallationDate: Installed on 2017-03-15 (4 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Alpha amd64 (20170311) SourcePackage: nvidia-prime UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1674304/+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