Desktop crashes when changing resolution

[Alan Pope 🍺🐧🐱 🦄]

Thinkpad X220 with docking bay with external display attached to it.
I frequently dock and undock my laptop while it's on.

Since about thursday (I think) the desktop becomes completely unusable when I dock or undock. The screen visibly corrupts, for example when undocking (and going from 1x1080p external screen to 1x768 internal panel) or docking. It flickers madly as if it's trying to crowbar 1920x1080 pixels into 1366x768 panel. Switching to VT and suspend/resume doesn't fix it.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-11.31-generic 3.13.3
Uname: Linux 3.13.0-11-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.13.2-0ubuntu5
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,grid,imgpng,gnomecompat,scale,workarounds,mousepoll,regex,wall,move,place,vpswitch,resize,unitymtgrabhandles,snap,session,expo,ezoom,unityshell]
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sat Feb 22 21:41:44 2014
DistUpgraded: 2014-01-20 08:54:25,315 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21da]
InstallationDate: Installed on 2012-06-29 (603 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MachineType: LENOVO 4287CTO
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-11-generic root=UUID=6088859e-4fc3-4ec8-903f-5b52cdc1d0eb ro quiet splash vt.handoff=7
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: Upgraded to trusty on 2014-01-20 (33 days ago)
dmi.bios.date: 12/05/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 8DET67WW (1.37 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4287CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8DET67WW(1.37):bd12/05/2012:svnLENOVO:pn4287CTO:pvrThinkPadX220:rvnLENOVO:rn4287CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4287CTO
dmi.product.version: ThinkPad X220
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.11+14.04.20140218-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.0~rc1-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.0~rc1-1ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.15.0-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu2
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: Sat Feb 22 21:40:07 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 728
 vendor LGD
xserver.version: 2:1.15.0-1ubuntu6

[Chris Wilson (ickle)]

Hmm, you are driving your panel at 1360x768 rather than its native 1368x768. It would not be the first time something strange happened trying to do so...

Can you please select 1366x768 as the panel resolution and see what happens?

[Alan Pope 🍺🐧🐱 🦄 (popey)]

I thought I was running it at native resolution. Gosh, seems not.

alan@deep-thought:~$ xrandr
Screen 0: minimum 320 x 200, current 1360 x 768, maximum 32767 x 32767
LVDS1 connected primary 1360x768+0+0 (normal left inverted right x axis y axis) 277mm x 156mm
   1366x768 60.0 +
   1360x768 59.8* 60.0
   1024x768 60.0
   800x600 60.3 56.2
   640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

When I just tried changing resolution without any docking/undocking - just using the display application it also went mental.

https://www.youtube.com/watch?v=UiU4I6oVgyg
https://www.youtube.com/watch?v=iAcyUHUyTt0

[Alan Pope 🍺🐧🐱 🦄 (popey)]

To be clear, it works fine at non-native 1360x768 and freaks out at native 1366x768.

[Chris Wilson (ickle)]

Can you please try (separately):

Option "TripleBuffer" "false"
Option "SwapbuffersWait" "false"

in its flickering mode (1366x768).

I suspect we are seeing the incomplete buffer when flickering. Either that or the hardware is just freaking out.

[Chris Wilson (ickle)]

Note afaik it should also display the same artifacts with 1360x768 if it was the bug in the software stack - so it seems possible that it is the hw freak out - but fixing sw is easier!

[Chris Wilson (ickle)]

Another option worth testing is:

Option "TearFree" "true"

That would rule out it being a hw pageflip issue if it works, since it too uses pageflips.

[Alan Pope 🍺🐧🐱 🦄 (popey)]

Well. Here's a funny thing. I was going mad last night trying all kinds of xorg options. On many occasions I'd get a black desktop after login - unity was dying. If I did get unity started then changing resolution would corrupt the display as reported in the bug. However I could login and change resolution as any other user. Other clues like getting the "welcome to dropbox" dialog on login led me to realise it was something broken with my profile.

I then started systematically moving/removing config from ~/.config/ and couldn't figure out what was breaking it. So I went on a bit of a rampage and removed all of ~/.config/nautilus and ~/.config/dconf. This "fixed" the problem. I can now login fine, and more importantly can change resolution, all with no changes to my xorg.conf (which I'd already reverted).

Sorry for wasting your time with this bug Chris!