Black screen after lock or switch user

[Dmitry Kann]

This started about a week ago, I started getting very frequent problems with lockscreen and switching users. After using either of them never brings the system back. Most of the time I just get a black screen (sometimes with mouse cursor).

The system seems to respond to keyboard but the display is broken. I have no clue whether it's xorg, lightdm or anything else.

This never happened until a few days ago.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xorg 1:7.7+1ubuntu8
ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4
Uname: Linux 3.13.0-32-generic i686
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.3
Architecture: i386
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: Thu Jul 31 10:42:04 2014
DistUpgraded: 2014-04-23 18:05:29,040 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 4.3.10, 3.13.0-27-generic, i686: installed
 virtualbox, 4.3.10, 3.13.0-29-generic, i686: installed
 virtualbox, 4.3.10, 3.13.0-30-generic, i686: installed
 virtualbox, 4.3.10, 3.13.0-31-generic, i686: installed
 virtualbox, 4.3.10, 3.13.0-32-generic, i686: installed
ExtraDebuggingInterest: Yes
GpuHangFrequency: Several times a day
GpuHangReproducibility: Occurs more often under certain circumstances
GpuHangStarted: Within the last few days
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] RV730/M96-XT [Mobility Radeon HD 4670] [1002:9488] (prog-if 00 [VGA controller])
   Subsystem: Apple Inc. Device [106b:00b6]
InstallationDate: Installed on 2011-10-06 (1028 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta i386 (20110921.2)
MachineType: Apple Inc. iMac10,1
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic root=UUID=61478576-72d6-40c8-81d0-3bf6629cc397 ro quiet splash reboot=pci vt.handoff=7
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
UpgradeStatus: Upgraded to trusty on 2014-04-23 (98 days ago)
dmi.bios.date: 09/03/09
dmi.bios.vendor: Apple Inc.
dmi.bios.version: IM101.88Z.00CC.B00.0909031926
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F2268DC8
dmi.board.vendor: Apple Inc.
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 13
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F2268DC8
dmi.modalias: dmi:bvnAppleInc.:bvrIM101.88Z.00CC.B00.0909031926:bd09/03/09:svnAppleInc.:pniMac10,1:pvr1.0:rvnAppleInc.:rnMac-F2268DC8:rvr:cvnAppleInc.:ct13:cvrMac-F2268DC8:
dmi.product.name: iMac10,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
version.compiz: compiz 1:0.9.11.2+14.04.20140714-0ubuntu1
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Thu Jul 31 10:23:05 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.15.1-0ubuntu2.1
xserver.video_driver: radeon

[penalvch (penalvch)]

Dmitry Kann, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal as it will automatically gather and attach updated debug information to this report:

apport-collect -p xorg 1350747

Please ensure you have xdiagnose installed, and that you click the Yes button for attaching additional debugging information.

As well, given the information from the prior release is already available, testing a release prior to the development one would not be helpful.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Dmitry Kann (yktooo)]

Well, after few upgrades through the years, I haven't seen it anymore. I think the bug can be closed.

[penalvch (penalvch)]

Dmitry Kann, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1350747/comments/3 regarding this being fixed with an update. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.