Forwarding this bug from Ubuntu reporter Stefano Rivera: http://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/717114 [Problem] With recent kernels a number of people are noticing various corruption in terminal programs. It appears there was a regression introduced with the introduction of the 2.6.38-1 kernel. The issue is irregular but affects text rendering by interlacing pixels from text elsewhere in the given text buffer when doing rapid scrolling of large quantities of text. This most often shows itself in terminal windows but can also be seen sometimes in firefox's rendered text. The issue seems to appear more often with compiz but has been seen in metacity. Only a minority of users seem to be reproducing the behavior, suggesting these users have some sort of hardware or configurational aspect in common, but so far the commonality between the users is not known. Perhaps it's an 64-bit-specific issue? Stefano bisected the problem and found this as the first commit where the misbehavior can be reproduced: commit 6bda10d152735c22baf1dcd92937420b4b0a359a Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Sun Dec 5 21:04:18 2010 +0000 drm/i915: Completely disable fence pipelining. I'm still seeing tiling corruption of PutImage and CopyArea (I think) under mutter on pnv, so obviously the pipelining logic is deeply flawed. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> [Original Description] Corruption seen in gnome-terminal. And also seen in the chromium tab-bar. Just caught one now with Firefox on slashdot (first try). The first time I reported this (in a comment on lp #710961), I was using Unity, but I'm back to GNOME with Compiz. > Do you recall more precisely when you started noticing it? I seem to remember it was very soon after your announcement [of moving to xorg-server 1.9.99, coinciding with an update from 2.6.37 to 2.6.38 on the kernel side], but I don't know why I didn't file it immediately then. Maybe I was waiting for Xorg to be uploaded too. Sorry, life in development releases means you run into quite a lot of bugs, and don't file them all immediately (hope someone else saw them and did the work). Just ran a bisection, and it pinpoints 6bda10d152735c22baf1dcd92937420b4b0a359a commit 6bda10d152735c22baf1dcd92937420b4b0a359a Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Sun Dec 5 21:04:18 2010 +0000 drm/i915: Completely disable fence pipelining. I'm still seeing tiling corruption of PutImage and CopyArea (I think) under mutter on pnv, so obviously the pipelining logic is deeply flawed. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Bisection log: See - https://bugs.launchpad.net/ubuntu/+bug/717114/comments/23 DistroRelease: Ubuntu 11.04 Package: xserver-xorg-video-intel 2:2.14.0-1ubuntu6 ProcVersionSignature: Ubuntu 2.6.38-3.30-generic 2.6.38-rc4 Uname: Linux 2.6.38-3-generic x86_64 Architecture: amd64 CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,scale,session,unityshell] CompositorRunning: compiz DRM.card0.DVI.D.1: status: disconnected enabled: disabled dpms: Off modes: edid-base64: DRM.card0.LVDS.1: status: connected enabled: enabled dpms: On modes: 1280x800 edid-base64: AP///////wAGEF+cAAAAAAgQAQOAHRJ4Ci8wl1hTiyklUFQAAAABAQEBAQEBAQEBAQEBAQEBvBsAoFAgFzAwIDYAHrMQAAAYAAAAAQAGECAAAAAAAAAAAAogAAAA/gBMUDEzM1dYMS1UTEExAAAA/gBDb2xvciBMQ0QKICAgAMI= DRM.card0.VGA.1: status: disconnected enabled: disabled dpms: Off modes: edid-base64: Date: Fri Feb 11 15:30:32 2011 DistUpgraded: Yes, recently upgraded Log time: 2009-12-11 10:51:59.838477 DistroCodename: natty DistroVariant: ubuntu DkmsStatus: GraphicsCard: Subsystem: Intel Corporation Device [8086:7270] Subsystem: Intel Corporation Device [8086:7270] MachineType: Apple Inc. MacBook2,1 ProcEnviron: LANGUAGE=en_ZA:en PATH=(custom, user) LANG=en_ZA.UTF-8 LC_MESSAGES=en_ZA.utf8ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-3-generic root=UUID=3345fa7f-d2c4-456f-8d0d-8fdb515433f7 ro quiet splash vt.handoff=7 Renderer: Hardware acceleration SourcePackage: xserver-xorg-video-intel dmi.bios.date: 06/27/07 dmi.bios.vendor: Apple Inc. dmi.bios.version: MB21.88Z.00A5.B07.0706270922 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: Mac-F4208CAA dmi.board.vendor: Apple Inc. dmi.board.version: PVT dmi.chassis.asset.tag: Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: Apple Inc. dmi.chassis.version: Mac-F4208CAA dmi.modalias: dmi:bvnAppleInc.:bvrMB21.88Z.00A5.B07.0706270922:bd06/27/07:svnAppleInc.:pnMacBook2,1:pvr1.0:rvnAppleInc.:rnMac-F4208CAA:rvrPVT:cvnAppleInc.:ct10:cvrMac-F4208CAA: dmi.product.name: MacBook2,1 dmi.product.version: 1.0 dmi.sys.vendor: Apple Inc. version.compiz: compiz 1:0.9.2.1+glibmainloop4-0ubuntu10 version.libdrm2: libdrm2 2.4.23-1ubuntu3 version.libgl1-mesa-glx: libgl1-mesa-glx 7.10-1ubuntu1 version.xserver-xorg: xserver-xorg 1:7.6~3ubuntu4 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.13.2+git20110124.fadee040-0ubuntu4 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-1ubuntu6 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu4
Created attachment 43684 [details] BootDmesg.txt
Created attachment 43685 [details] CurrentDmesg.txt
Created attachment 43686 [details] XorgLog.txt
Created attachment 43687 [details] Still-Present.png Screenshot. Notice the lines of pixels through certain text elements. These appear sometimes when scrolling rapidly.
(Fwiw, we've gotten some other bug reports relating to terminal corruption regressions, which may or may not be related, but I'm keeping them separate for now.)
*** Bug 34714 has been marked as a duplicate of this bug. ***
I reported #34714 but I'm pretty sure this is the same issue. It's not a 64bit issue btw, I have it on my 32bit netbook.
I'm optimistic that commit 467cffba85791cdfce38c124d75bd578f4bb8625 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Mon Mar 7 10:42:03 2011 +0000 drm/i915: Rebind the buffer if its alignment constraints changes with tiling Early gen3 and gen2 chipset do not have the relaxed per-surface tiling constraints of the later chipsets, so we need to check that the GTT alignment is correct for the new tiling. If it is not, we need to rebind. Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> will have had some positive impact on a few of these corruptions...
(In reply to comment #8) > I'm optimistic that > commit 467cffba85791cdfce38c124d75bd578f4bb8625 > will have had some positive impact on a few of these corruptions... Hard to say if it has, I still see lots of corruption. I tested with the Ubuntu 2.6.38-6.34 kernel + 467cffba85791cdfce38c124d75bd578f4bb8625.
Can confirm that this corruption is still present in the Ubuntu-2.6.38-7.35 kernel which is v2.6.38 based and contains Chris' fix.
In the Ubuntu bug it has been suggested that reverting commit 6bda10d152735c22baf1dcd92937420b4b0a359a helps with this corruption. I can confirm that reverting that does indeed eliminate the corruption in terminal windows for me, _however_ I then get corruption elsewhere mostly in icons for flies on the desktop and on chromiums toolbar icons as they change colour; mostly a striated look, as if incorrectly tiled.
Created attachment 44535 [details] [review] Reorder the pipelined flush Had a chat with Andy Whitcroft and we put together this patch for testing, there will be a Ubuntu kernel availably shortly.
(In reply to comment #12) > Created an attachment (id=44535) [details] > Reorder the pipelined flush > > Had a chat with Andy Whitcroft and we put together this patch for testing, > there will be a Ubuntu kernel availably shortly. Makes a massive difference. I haven't seen any corruption with this patch.
Created attachment 44552 [details] [review] Fix piplelined fence corruption A second variant I want to try. Hopefully this introduces far fewer stalls than the first.
Created attachment 44553 [details] [review] Fix piplelined fence corruption
Created attachment 44574 [details] [review] Fix tiling corruption New version for linus/master
Working on the theory that it is one and the same bug: commit b5b5ac2dec49ea5ae033434efa90863aa5cdfb2c Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Thu Mar 17 15:23:22 2011 +0000 drm/i915: Fix tiling corruption from pipelined fencing ... even though it was disabled. A mistake in the handling of fence reuse caused us to skip the vital delay of waiting for the object to finish rendering before changing the register. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34584 Cc: Andy Whitcroft <apw@canonical.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> [Note for 2.6.38-stable, we need to reintroduce the interruptible passing] Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Dave Airlie <airlied@linux.ie>
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