I don't know how to reproduce this issue. It might be related to the
nouveau driver, because after I enabled the proprietary driver from nVidia,
I haven't experience the issue.

It happened approximately once or twice a day.
2015. dec. 18. du. 4:56 ezt írta ("Christopher M. Penalver" <
<email address hidden>>):

> Radics Ottó, thank you for reporting this and helping make Ubuntu
> better.
>
> Could you please advise on how to reproduce this specifically?
>
> Also, how often does this occur?
>
> ** Package changed: xorg (Ubuntu) => xserver-xorg-video-intel (Ubuntu)
>
> ** Changed in: xserver-xorg-video-intel (Ubuntu)
>    Importance: Undecided => Medium
>
> ** Changed in: xserver-xorg-video-intel (Ubuntu)
>        Status: New => Incomplete
>
> ** Description changed:
>
>   I got a black screen and after a while login screen appeared.
> +
> + Backtrace -> https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-
> + video-intel/+bug/1519522/+attachment/4524927/+files/XorgLogOld.txt
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 15.10
>   Package: xorg 1:7.7+7ubuntu4
>   ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
>   Uname: Linux 4.2.0-18-generic x86_64
>   .tmp.unity.support.test.0:
> -
> +
>   ApportVersion: 2.19.1-0ubuntu5
>   Architecture: amd64
>   CompizPlugins: No value set for
> `/apps/compiz-1/general/screen0/options/active_plugins'
>   CompositorRunning: compiz
>   CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
>   CompositorUnredirectFSW: true
>   CurrentDesktop: Unity
>   Date: Tue Nov 24 23:22:50 2015
>   DistUpgraded: Fresh install
>   DistroCodename: wily
>   DistroVariant: ubuntu
>   DkmsStatus:
> -  bbswitch, 0.8, 4.2.0-18-generic, x86_64: installed
> -  nvidia-304, 304.131, 4.2.0-18-generic, x86_64: installed
> -  virtualbox, 5.0.4, 4.2.0-18-generic, x86_64: installed
> +  bbswitch, 0.8, 4.2.0-18-generic, x86_64: installed
> +  nvidia-304, 304.131, 4.2.0-18-generic, x86_64: installed
> +  virtualbox, 5.0.4, 4.2.0-18-generic, x86_64: installed
>   ExtraDebuggingInterest: I just need to know a workaround
>   GraphicsCard:
> -  Intel Corporation 4th Gen Core Processor Integrated Graphics Controller
> [8086:0416] (rev 06) (prog-if 00 [VGA controller])
> -    Subsystem: Dell Device [1028:05fe]
> +  Intel Corporation 4th Gen Core Processor Integrated Graphics Controller
> [8086:0416] (rev 06) (prog-if 00 [VGA controller])
> +    Subsystem: Dell Device [1028:05fe]
>   InstallationDate: Installed on 2015-07-04 (142 days ago)
>   InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
>   MachineType: Dell Inc. XPS 15 9530
>   ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=904a0ffb-8477-46ae-bbb8-775512ba4e95 ro quiet splash vt.handoff=7
>   SourcePackage: xorg
>   Symptom: display
>   Title: Xorg crash
>   UdevLog: Error: [Errno 2] Nincs ilyen fájl vagy könyvtár: '/var/log/udev'
>   UpgradeStatus: No upgrade log present (probably fresh install)
>   dmi.bios.date: 07/30/2015
>   dmi.bios.vendor: Dell Inc.
>   dmi.bios.version: A09
>   dmi.board.name: XPS 15 9530
>   dmi.board.vendor: Dell Inc.
>   dmi.board.version: A09
>   dmi.chassis.type: 8
>   dmi.chassis.vendor: Dell Inc.
>   dmi.chassis.version: Not Specified
>   dmi.modalias:
> dmi:bvnDellInc.:bvrA09:bd07/30/2015:svnDellInc.:pnXPS159530:pvrA09:rvnDellInc.:rnXPS159530:rvrA09:cvnDellInc.:ct8:cvrNotSpecified:
>   dmi.product.name: XPS 15 9530
>   dmi.product.version: A09
>   dmi.sys.vendor: Dell Inc.
>   version.compiz: compiz 1:0.9.12.2+15.10.20151015-0ubuntu1
>   version.ia32-libs: ia32-libs N/A
>   version.libdrm2: libdrm2 2.4.64-1
>   version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.2-1ubuntu4
>   version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
>   version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.2-1ubuntu4
>   version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu9
>   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+git20150808-0ubuntu4
>   version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau
> 1:1.0.11-1ubuntu3
>   xserver.bootTime: Tue Nov 24 23:22:36 2015
>   xserver.configfile: default
>   xserver.errors:
> -
> +
>   xserver.logfile: /var/log/Xorg.0.log
>   xserver.outputs:
> -  product id                                5169
> -  vendor                                     SHP
> +  product id                                5169
> +  vendor                                     SHP
>   xserver.version: 2:1.17.2-1ubuntu9
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1519522
>
> Title:
>   Xorg crashes
>
> To manage notifications about this bug go to:
>
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>