I have, I think, a reliable way to trigger this behavior, if that helps. It requires a non-trivial setup, though.
I have gnome-shell running on dual monitors. The first is 1920x1200, the second is 1920x1080 (not sure if the resolution difference matters). If I run a full-screen game on The 1920x1200 monitor, I get freezes, and notes in the dmesg about hangcheck timers and kickrings ("stuck wait on blitter ring"). I believe OpenGL acceleration of the desktop is important, because the freezes are not triggered in fluxbox, for instance. I'm not sure if the game itself needs to be using OpenGL, or if the full-screen window is the triggering factor, or something else entirely. It is important that the game keep the monitors distinct, and only go full screen on one. I just tried it on Battle for Wesnoth, and full screen there sets the monitors to mirror, which doesn't trigger the problem. This is on an i7 4770, if that matters. I realize this is may be difficult to put together for a test setup, but I thought I'd mention it. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1041790 Title: [snb] GPU lockup IPEHR: 0x0b160001 IPEHR: 0x0b140001, workaround i915.semaphores=0 Status in X.org xf86-video-intel: Confirmed Status in “linux” package in Ubuntu: Confirmed Status in “sandybridge-meta” package in Ubuntu: Confirmed Status in “xserver-xorg-video-intel” package in Ubuntu: Triaged Bug description: X locks up periodically for a 2 to ten seconds at a time and this crash log gets generated. It's significantly more than several times a day but not quite continuous. Temporarily disabiling semaphores seems to eliminate the problem. E.g.: $ sudo -s # echo 0 > /sys/modules/i915/parameters/semaphores [Workaround] 1. Edit your /etc/default/grub file. 2. Change this line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.semaphores=0" 3. Then run sudo update-grub 4. And reboot If you indeed have this bug, that should stop the lockups from happening. If it doesn't, then file a new bug report. Side Effects: Rendering throughput is dropped by 10% with SNA, or as much as 3x with UXA. OpenGL performance is likely to be reduced by about 30%. More CPU time is spent waiting for the GPU with rc6 disabled, so increased power consumption. [Original Report] ProblemType: Crash DistroRelease: Ubuntu 12.10 Package: xserver-xorg-video-intel 2:2.20.3-0ubuntu1 Uname: Linux 3.6.0-rc3-git-20120826.1015 x86_64 ApportVersion: 2.5.1-0ubuntu2 Architecture: amd64 Chipset: sandybridge-m-gt2 Date: Sun Aug 26 16:06:32 2012 DistroCodename: quantal DistroVariant: ubuntu DuplicateSignature: [sandybridge-m-gt2] GPU lockup IPEHR: 0x0b160001 IPEHR: 0x0b140001 Ubuntu 12.10 EcryptfsInUse: Yes ExecutablePath: /usr/share/apport/apport-gpu-error-intel.py GpuHangFrequency: Continuously InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120724.2) InterpreterPath: /usr/bin/python3.2mu MachineType: Dell Inc. Dell System XPS L502X ProcCmdline: /usr/bin/python3 /usr/share/apport/apport-gpu-error-intel.py ProcEnviron: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.6.0-rc3-git-20120826.1015 root=UUID=135c8090-427c-460a-909d-eff262cd44b6 ro quiet splash vt.handoff=7 RelatedPackageVersions: xserver-xorg 1:7.7+1ubuntu3 libdrm2 2.4.38-0ubuntu2 xserver-xorg-video-intel 2:2.20.3-0ubuntu1 SourcePackage: xserver-xorg-video-intel Title: [sandybridge-m-gt2] GPU lockup IPEHR: 0x0b160001 IPEHR: 0x0b140001 UdevDb: Error: [Errno 2] No such file or directory: 'udevadm' UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: dmi.bios.date: 05/29/2012 dmi.bios.vendor: Dell Inc. dmi.bios.version: A11 dmi.board.name: 0NJT03 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: 0.1 dmi.modalias: dmi:bvnDellInc.:bvrA11:bd05/29/2012:svnDellInc.:pnDellSystemXPSL502X:pvr:rvnDellInc.:rn0NJT03:rvrA00:cvnDellInc.:ct8:cvr0.1: dmi.product.name: Dell System XPS L502X dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/xserver-xorg-video-intel/+bug/1041790/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp