xserver crash in drm_vblank_count_and_time

[Rick Spencer]

Call Trace:
 ? drm_wait_vblank+0x21a/0x5c0
 ? try_to_wake_up+0x2a0/0x2a0
 drm_ioctl+0x4e9/0x5b0
 ? drm_modeset_ctl+0x70/0x70
 do_vfs_ioctl+0x99/0x570
 sys_ioctl+0x91/0xb0
 ? sys_read+0x6b/0xa0
 system_call_fastpath+0x1a/0x1f

RIP drm_vblank_count_and_time+0xd/0x60

[Original Report]
Starting some weeks ago my graphics has been misbehaving a bit. This started with starting in low graphics mode from time to time, or booting to a VT instead of the LightDM greeter. Today I had a complete crash while running a Google Hangout. I've attached a picture of the screen output in case that's helpful.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: xorg 1:7.7+1ubuntu4
ProcVersionSignature: Ubuntu 3.8.0-7.15-generic 3.8.0
Uname: Linux 3.8.0-7-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.8-0ubuntu4
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
Date: Thu Feb 28 16:45:28 2013
DistUpgraded: 2013-02-05 13:12:39,470 DEBUG enabling apt cron job
DistroCodename: raring
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 03) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:0279]
   Subsystem: Dell Device [1028:0279]
InstallationDate: Installed on 2012-11-04 (116 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: Dell Inc. Studio Hybrid 140g
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.8.0-7-generic root=UUID=e4eb06cb-d4ba-40c3-ac8f-7af8f0973b69 ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to raring on 2013-02-05 (23 days ago)
dmi.bios.date: 09/26/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.0.6
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 0P096C
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 3
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: '01'
dmi.modalias: dmi:bvnDellInc.:bvr1.0.6:bd09/26/2008:svnDellInc.:pnStudioHybrid140g:pvr00:rvnDellInc.:rn0P096C:rvrA01:cvnDellInc.:ct3:cvr'01':
dmi.product.name: Studio Hybrid 140g
dmi.product.version: 00
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.9~daily13.02.19-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.42-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0.2-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0.2-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.13.2-0ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.3-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.6-0ubuntu3
xserver.bootTime: Thu Feb 28 16:04:53 2013
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.13.2-0ubuntu2
xserver.video_driver: intel

[Bryce Harrington (bryce)]

The low graphics and VT boots sound like the drm race condition bug #982889. There is a workaround posted in comment #5, and I've coded what I think is a possible fix. The fix is in a PPA, but I'm waiting on someone to test it to verify it does fix it before I upload it. (I'm not 100% certain it will fix the issue for all cases, maybe just certain failure modes.)

The crash in the photo might be an unrelated bug, since it occurs during regular system usage. (#982889 happens only at boot). I'm not seeing other reports about it though. Let's focus this bug report on that issue.

[Chris Wilson (ickle)]

Does anyone have that kernel handy to do an address lookup?

The prime candidates for the crash all look suspect as they are deferenced earlier in the callchain, so the OOPS is not making sense.

[Kamal Mostafa (kamalmostafa)]

@Chris-

Here's the kernel in question:
https://launchpad.net/ubuntu/+source/linux/3.8.0-7.15/+build/4318151
http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-raring.git;a=shortlog;h=refs/tags/Ubuntu-3.8.0-7.15

I've attached the disassembled drm_vblank_count_and_time() from that. I'm confused as to why the oops RIP shows as drm_vblank_count_and_time+0xd/0x60 but 0xd doesn't seem to land on an instruction boundary in drm_vblank_count_and_time.

[Kamal Mostafa (kamalmostafa)]

Attached is the the same disassembly of drm_vblank_count_and_time, but with objdump --show-raw-insn to include the raw opcodes.

[Rick Spencer (rick-rickspencer3)]

I've been updating regularly. I haven't seen any video issues for a week or so. This no longer seems to be happening to me.

[Chris Wilson (ickle)]

None of us can explain the oops, which is worrisome. So lets cross our fingers and hope it never happens again. If it does, hopefully we can establish a pattern and work out the cause.

[bugbot (bugbot)]

We're closing this bug since there has not been a response from the original reporter. However, the issue still exists please feel free to reopen with the requested information. If you're not the original reporter, we'd prefer you file a new bug report.

Some tips:

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  * Test against the latest development Ubuntu. http://cdimage.ubuntu.com/daily-live/
    Bugs marked as affecting the development version tend to get priority attention.

  * The `xdiagnose` utility has functionality for enabling debugging and
    analyzing a few common X problems.

  * Tag your bugs with the Ubuntu versions you have reproduced the issue in.

  * See https://wiki.ubuntu.com/X/Reporting for tips on writing good bug reports.