I believe this may be a kernel regression. I can repro on 15.04 with sddm by installing any 4.x series kernel, haven't done any bisecting, and can't find anything interesting in dmesg (when I can switch to a vc sucessfully after X starts but fails to output anything), but with a single change from 3.19 to any of the mainline PPA 4.x kernels, the problem is immediately evident, and occasinally CPU locks up (SKL), but only when both GPUs are enabled (I have a BIOS hardware mux that I can use to force Nvidia only, which is what I'm doing currently to have a usable system and avoid recompiling iwl 8260 drivers for 3.19 every kernel update).
-- 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/1501041 Title: No visible display in non gnome sessions when using nvidia drivers via nvidia-prime until screen goes to sleep, then waked up Status in Light Display Manager: Confirmed Status in lightdm package in Ubuntu: Triaged Status in nvidia-graphics-drivers package in Ubuntu: Invalid Status in ubuntu-drivers-common package in Ubuntu: Triaged Status in unity-greeter package in Ubuntu: Invalid Status in xfce4-session package in Ubuntu: Invalid Status in xorg-server package in Ubuntu: Incomplete Bug description: ** this appears to be that the display is blanked/asleep at greeter & login. Forcing or waiting for screen to blank/sleep then waking up restores display See comments 8 & 10 for further info, demonstrations ** Please note that this bug is being filed on a recent 15.10 Ubuntu image install but from a gnome session In a nutshell - Once nividia drivers are installed & used from nvidia-prime there is no longer a visible display in unity-greeter nor in an ubuntu session once logged in. (a blind log in successfully loads an ubuntu session. Everything in the ubuntu session works fine, there are no errors & all the related logs look ok, there is just no visible display. I can open apps, run commands, copy/create logs, play music, play videos, just no display so has to be done blindly from keyboard. On the other hand if I install gnome-shell & log in (blindly) to a gnome session from greeter then all is well & I get a visible display. The same behaviour is seen on an Xubuntu image install, once nvidia is installed & switched to, no visible display. Again there installing & logging into a gnome session works fine with visible display nvidia driver version doesn't matter, exact same is seen with current 15.10 versions & the one I'm currently using (355) from drivers ppa. ** this appears to be that the display is blanked/asleep at greeter & login. Forcing or waiting for screen to blank/sleep then waking up restores display See comment 8 for further info ** ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: xserver-xorg-core 2:1.17.2-1ubuntu7 ProcVersionSignature: Ubuntu 4.2.0-11.13-generic 4.2.1 Uname: Linux 4.2.0-11-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.19-0ubuntu1 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: None CurrentDesktop: GNOME Date: Tue Sep 29 16:15:21 2015 DistUpgraded: Fresh install DistroCodename: wily DistroVariant: ubuntu DkmsStatus: bbswitch, 0.7, 4.2.0-11-generic, x86_64: installed nvidia-355, 355.11, 4.2.0-11-generic, x86_64: installed ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller]) Subsystem: Lenovo Device [17aa:3801] NVIDIA Corporation GK107M [GeForce GT 755M] [10de:0fcd] (rev ff) (prog-if ff) InstallationDate: Installed on 2015-09-28 (0 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20150928) MachineType: LENOVO 20217 ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-11-generic.efi.signed root=UUID=3712249e-a4c8-4b29-9ffb-f9f9e7d5259a ro quiet splash vt.handoff=7 SourcePackage: xorg-server UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 09/18/2013 dmi.bios.vendor: LENOVO dmi.bios.version: 74CN44WW(V3.05) dmi.board.asset.tag: No Asset Tag dmi.board.name: VIQY0Y1 dmi.board.vendor: LENOVO dmi.board.version: 31900058STD dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Lenovo IdeaPad Y510P dmi.modalias: dmi:bvnLENOVO:bvr74CN44WW(V3.05):bd09/18/2013:svnLENOVO:pn20217:pvrLenovoIdeaPadY510P:rvnLENOVO:rnVIQY0Y1:rvr31900058STD:cvnLENOVO:ct10:cvrLenovoIdeaPadY510P: dmi.product.name: 20217 dmi.product.version: Lenovo IdeaPad Y510P dmi.sys.vendor: LENOVO version.compiz: compiz 1:0.9.12.2+15.10.20150908-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.64-1 version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.0-1ubuntu1 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.0-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu7 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20150808-0ubuntu2 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3 xserver.bootTime: Tue Sep 29 16:05:24 2015 xserver.configfile: default xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: product id 729 vendor LGD xserver.version: 2:1.17.2-1ubuntu7 To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1501041/+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
