System freezes after returning from locked screen

[Rob Moore]

Quite frequently when I lock my screen (or it locks itself) and I unlock it the system is responsive for a few seconds but then completely freezes. I can't reboot but have to turn off the power on the machine.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+13ubuntu3
ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset wl nvidia
.proc.driver.nvidia.gpus.0000.02.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:02:00.0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 361.42 Tue Mar 22 18:10:58 PDT 2016
 GCC version: gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2)
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2
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: Wed May 18 11:24:59 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
DkmsStatus:
 bbswitch, 0.8, 4.4.0-22-generic, x86_64: installed
 bcmwl, 6.30.223.248+bdcom, 4.4.0-21-generic, x86_64: installed
 bcmwl, 6.30.223.248+bdcom, 4.4.0-22-generic, x86_64: installed
 nvidia-361, 361.42, 4.4.0-22-generic, x86_64: installed
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: Dell 4th Gen Core Processor Integrated Graphics Controller [1028:060d]
   Subsystem: Dell GK107GLM [Quadro K1100M] [1028:060d]
InstallationDate: Installed on 2016-04-10 (37 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
MachineType: Dell Inc. Dell Precision M3800
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-22-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/17/2015
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: Dell Precision M3800
dmi.board.vendor: Dell Inc.
dmi.board.version: A10
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: Not Specified
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd08/17/2015:svnDellInc.:pnDellPrecisionM3800:pvrA10:rvnDellInc.:rnDellPrecisionM3800:rvrA10:cvnDellInc.:ct8:cvrNotSpecified:
dmi.product.name: Dell Precision M3800
dmi.product.version: A10
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.12.2+16.04.20160415-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.18.3-1ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160325-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2

[penalvch (penalvch)]

Rob Moore, thank you for reporting this and helping make Ubuntu better.

Could you please capture the crash following https://help.ubuntu.com/community/DebuggingSystemCrash ?

[Rob Moore (roborative)]

I experienced this issue (or something similar) yesterday. I used the alt-sysrq-1 and alt-sysrq-t combo mentioned in the document linked to in the last comment and after sometime the machine started responding again. I captured the kern.log and will attach it here in case it's useful.

[penalvch (penalvch)]

Rob Moore, in order to allow additional upstream developers to examine the issue, at your earliest convenience, could you please test the latest upstream kernel available from http://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D ? Please keep in mind the following:
1) The one to test is at the very top line at the top of the page (not the daily folder).
2) The release names are irrelevant.
3) The folder time stamps aren't indicative of when the kernel actually was released upstream.
4) Install instructions are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds .

If testing on your main install would be inconvenient, one may:
1) Install Ubuntu to a different partition and then test this there.
2) Backup, or clone the primary install.

If the latest kernel did not allow you to test to the issue (ex. you couldn't boot into the OS) please make a comment in your report about this, and continue to test the next most recent kernel version until you can test to the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this issue is fixed in the mainline kernel, please add the following tags by clicking on the yellow circle with a black pencil icon, next to the word Tags, located at the bottom of the report description:
kernel-fixed-upstream
kernel-fixed-upstream-X.Y-rcZ

Where X, and Y are the first two numbers of the kernel version, and Z is the release candidate number if it exists.

If the mainline kernel does not fix the issue, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-X.Y-rcZ

Please note, an error to install the kernel does not fit the criteria of kernel-bug-exists-upstream.

Also, you don't need to apport-collect further unless specifically requested to do so.

Once testing of the latest upstream kernel is complete, please mark this report Status Confirmed. Please let us know your results.

Thank you for your understanding.

[Launchpad Janitor (janitor)]

[Expired for xorg (Ubuntu) because there has been no activity for 60 days.]