Bug 367766

I have the same issue with my Quadro M1000M. I created this bug in Arch: https://bugs.kde.org/show_bug.cgi?id=367766

> Compositing should work. Worked with previous driver (367.35).

So I understand correctly that this is a driver regression? Then you should report it against NVIDIA. Sorry but if our code didn't change it's hardly a problem we can solve.

From the detection it looks everything is fine - everything is detected correctly.

Nevertheless thanks to making us aware of that problem, we might need to tell people about it...

Adding some useful debug output which teo just provided me:
% kwin_x11 --replace
QXcbConnection: XCB error: 3 (BadWindow), sequence: 3651, resource id: 10485848, major code: 18 (ChangeProperty), minor code: 0
OpenGL vendor string:                   NVIDIA Corporation                                                                                                                                                                      
OpenGL renderer string:                 Quadro M2000M/PCIe/SSE2                                                                                                                                                                 
OpenGL version string:                  3.1.0 NVIDIA 370.23
OpenGL shading language version string: 1.40 NVIDIA via Cg compiler
Driver:                                 NVIDIA
Driver version:                         370.23
GPU class:                              Unknown
OpenGL version:                         3.1
GLSL version:                           1.40
X server version:                       1.18.4
Linux kernel version:                   4.7.1
Requires strict binding:                no
GLSL shaders:                           yes
Texture NPOT support:                   yes
Virtual Machine:                        no
Pixel was QVector4D(0, 0, 0, 0) expected QVector4D(0, 1, 0, 1)
Pixel was QVector4D(0, 0, 0, 0) expected QVector4D(0, 1, 0, 1)
Pixel was QVector4D(0, 0, 0, 0) expected QVector4D(0, 1, 0, 1)
Pixel was QVector4D(0, 0, 0, 0) expected QVector4D(0, 1, 0, 1)
kwin_core: ShaderManager self test failed
kwin_core: Failed to initialize compositing, compositing disabled


We can see it hits the shader self test failure

Workaround for the issue at https://phabricator.kde.org/D2744

Git commit e9e936b6c1bde338fb51ea3ada0897ad70055c44 by Martin Gräßlin.
Committed on 12/09/2016 at 11:13.
Pushed by graesslin into branch 'Plasma/5.7'.

[kwinglutils] Skip ShaderManager::selfTest for NVIDIA Quadro hardware

Summary:
The self test fails with NVDIDA 370.23 or newer on Quadro hardware.
Most likely there is a bug in our code as the same things work later on.
But without the hardware we are not able to reproduce and investigate
properly. Given that all we currently can do is to skip the self test.

We encourage users to investigate this properly and to help us to
identify the root issue, so that we can fix it.

Reviewers: #kwin

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D2744

M  +4    -0    libkwineffects/kwinglutils.cpp

http://commits.kde.org/kwin/e9e936b6c1bde338fb51ea3ada0897ad70055c44

> The self test fails with NVDIDA 370.23 or newer on Quadro hardware.
> Most likely there is a bug in our code as the same things work later on.
> But without the hardware we are not able to reproduce and investigate
> properly. Given that all we currently can do is to skip the self test.

I'm happy to help you fix this bug for real. Ping me on IRC -- #zx2c4 -- and we can run various tests.

Just wanted to chime in - working now on 5.7.5 and the 5.8 beta. Also, let me know if you need anymore help debugging for the "real" fix.

>  Also, let me know if you need anymore help debugging for the "real" fix.

Sure, we would love to figure out what's the real problem. For that we need someone with an affected system and slight knowledge about OpenGL. Something is going wrong when rendering the first frame - some state being wrong, incorrect fencing, something like that. So it needs someone to go through the rendering of the first frame to figure that one out.

Unfortunately creating patches and passing them to someone else for testing doesn't bring us anywhere - we tried that already.

So, I have an affected system, but not the slightest knowledge of OpenGL, unfortunately - last time I came close to that was messing around with SDL 1.2 years ago.

In my case Kwin doesn't even seem to recognize the presence of the nvidia driver.

I have an NVS 510 card with 370.28 driver. The driver loads fine but Kwin uses the LLVMpipe. This is happening with KF 5.8.0, was fine before.

Not sure if it's related to this bug or should I open another one. More detailed report on https://bbs.archlinux.org/viewtopic.php?id=218038

@Andrej: if llvmpipe is loaded it means that the driver doesn't work. That's a setup problem and completely unrelated to the problem described in this bug report.

@Martin: You're right, a package dependency didn't resolve properly during an upgrade it seems. Thanks and sorry for false alarm.