Dear Maintainer,

Application: kwin (4.6.5 (4.6.5))
KDE Platform Version: 4.6.5 (4.6.5)
Qt Version: 4.7.3
Operating System: Linux 3.0.0-1-amd64 x86_64
Distribution: Debian GNU/Linux unstable (sid)

As the link (http://www.phoronix.com/scan.php?page=news_item&px=OTM0NA), given
by Martin Steigerwald  on the debian-kde mailing list (
http://lists.debian.org/debian-kde/2011/08/msg00070.html), says this bug
affects all Intel graphic cards.

My laptop does not have sandybridge architecture and has been affected by
this problem. I also have a desktop with Intel chipset at work that has been
affected. Both machines are running Debian testing.

The fix given works fine on my laptop, however on the work desktop
everything gets slow. I installed Debian on that desktop this week so I
don't know if it is slow 'cause of this bug or some other factor. On the
laptop kwin has worked fine for years now, so all I had to do was to set the
environment variable and everything is back to normal.

This mail has been written from my laptop, here's the system info:

Hello,

I can confirm the very same problem on my Thinkpad 420s (Sandy Bridge)
with the very same software and library versions. All versions of
related are up to date. This is my backtrace:


Application: KWin (kwin), signal: Segmentation fault
[KCrash Handler]
#6  __memcpy_ssse3 () at ../sysdeps/x86_64/multiarch/memcpy-ssse3.S:91
#7  0x00007f64bcd98d4b in __indirect_glProgramParameters4fvNV
(target=34156096, index=135520, num=557073152, params=0x21160) at
indirect.c:9317
#8  0x00007f64a53c6aaf in KWin::ARBBlurShader::init (this=0x2106380) at
../../../kwin/effects/blur/blurshader.cpp:473
#9  0x00007f64a53c3e1b in KWin::BlurEffect::reconfigure (this=0x2108970,
flags=<optimized out>) at ../../../kwin/effects/blur/blur.cpp:76
#10 0x00007f64a53c3fa7 in KWin::BlurEffect::BlurEffect (this=0x2108970)
at ../../../kwin/effects/blur/blur.cpp:48
#11 0x00007f64a53c4056 in KWin::effect_create_kwin4_effect_blur () at
../../../kwin/effects/blur/blur.cpp:29
#12 0x00007f64bf8a6471 in KWin::EffectsHandlerImpl::loadEffect
(this=0x2077e90, name=...) at ../../kwin/effects.cpp:1128
#13 0x00007f64bf8a7531 in KWin::EffectsHandlerImpl::reconfigure
(this=0x2077e90) at ../../kwin/effects.cpp:143
#14 0x00007f64bf88131a in KWin::Workspace::setupCompositing
(this=0x7f64a0007be0) at ../../kwin/composite.cpp:216
#15 0x00007f64bf805733 in KWin::Workspace::Workspace
(this=0x7f64a0007be0, restore=false) at ../../kwin/workspace.cpp:222
#16 0x00007f64bf81c7ca in KWin::Application::Application
(this=<optimized out>) at ../../kwin/main.cpp:331
#17 0x00007f64bf81e4db in kdemain (argc=<optimized out>, argv=<optimized
out>) at ../../kwin/main.cpp:506
#18 0x00007f64bf45cead in __libc_start_main (main=<optimized out>,
argc=<optimized out>, ubp_av=<optimized out>, init=<optimized out>,
fini=<optimized out>, rtld_fini=<optimized out>,
stack_end=0x7fff9a709f98) at libc-start.c:228
#19 0x00000000004006b1 in _start ()


It's interesting to point out I /didn't/ have this problem until I
upgraded today. Before upgrading related package versions have been:

2011-11-22 00:32:14 upgrade libgl1-mesa-glx 7.10.2-3 7.11-6
2011-11-22 01:36:01 upgrade kde-window-manager 4:4.6.3-1 4:4.6.5-3


After upgrade:

kde-window-manager 4:4.6.5-3
libgl1-mesa-glx    7.11-6

Hi,

Arno Töll <debian@toell.net> (22/11/2011):

you may wanna check what happens with mesa 7.11.$n stable releases.

Mraw,
KiBi.

Hi KiBi,

just for the sake of completeness as I already said it in IRC: Upgrading
libgl1-mesa-glx to 7.11.1-1 does not solve the problem and causes the
same problems. Forcing KDE's kwin to use direct rendering still works
though.