Bug 46956

Summary:	Selecting 2xAntiAliasing causes Nexuiz to crash "X Error: BadMatch, failed request (X_CreateWindow)"
Product:	Mesa	Reporter:	Emil Velikov <emil.l.velikov>
Component:	Drivers/DRI/nouveau	Assignee:	Nouveau Project <nouveau>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium
Version:	git
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	Nexuiz console output nv50_screen_is_format_supported - debug info nv50_screen_is_format_supported - debug info, disallow sample_count=2 Patch to disable MS visuals.

Description Emil Velikov 2012-03-04 06:01:43 UTC

Created attachment 58004 [details]
Nexuiz console output

How to:
1. Startup Nexuiz
2. Select Settings>Effects
3. Set Antialiasing to 2x
4. Click Apply immediately
5. Observe the crash

Issue is not present when
* 0xAA, 4xAA mode is selected in Nexuiz
* Software rendering is used - LIBGL_ALWAYS_SOFTWARE=1

Issue is independent on
* kernel version
* direct/indirect rendering - LIBGL_ALWAYS_INDIRECT=1 makes no difference
* Desktop enviroment - Gnome3, fluxbox


Distribution - Arch x86-64
Nexuiz - 2.5.2 Nexuiz Linux 02:51:06 Oct  1 2009 9271 release
kernel - 3.0.22 / 3.2.8 / nouveau-git
libdrm - 2.4.31
Mesa - 95594bae47d8b3302be188e6f0be2d69c5507bb3
xf86-video-nouveau - b0d7f4ddd94154491d04dcb9698d63d61e9240d
Xorg - 1.11.4



The issue was bisected to

commit b2dcf880e8bcd61be59602f5a2d18c77a5fc60c1
Author: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Date:   Mon Jul 11 18:02:27 2011 +0200

    nv50,nvc0: add support for multi-sample resources

Comment 1 Emil Velikov 2012-03-04 06:19:15 UTC

Created attachment 58005 [details]
nv50_screen_is_format_supported - debug info

Comment 2 Emil Velikov 2012-03-04 06:21:40 UTC

Created attachment 58006 [details]
nv50_screen_is_format_supported - debug info, disallow sample_count=2

Nexuiz works great if we return False when sample_count is 2

Comment 3 Emil Velikov 2012-03-04 06:24:32 UTC

IMHO this is a mesa and/or X fault, although I'm out of ideas

I'm happy to test any patches/provide any additional information

Thanks
Emil

Comment 4 Christoph Bumiller 2012-03-04 08:53:54 UTC

Created attachment 58007 [details]
Patch to disable MS visuals.

Does that help ?

Comment 5 Emil Velikov 2012-03-04 12:05:50 UTC

Works like a charm

Note: Nexuiz complains about
"Couldn't get an RGB, Double-buffered, Depth visual"

Although everything works as expected


Thanks
Emil

Comment 6 Emil Velikov 2012-03-14 12:59:19 UTC

The issue exists in xonotic 0.6 (nexuiz fork)

I would not mind filing the bug in xonotic if it is an application issue

Regards
Emil

Comment 7 Emil Velikov 2012-05-29 12:47:09 UTC

Thank you, the issue was resolved by

commit f80c2874eca86a12517fbe2f4c15287edfb4dc89
Author: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Date:   Mon May 21 23:46:11 2012 +0200

    gallium: add st_api feature mask to prevent advertising MS visuals
    
    v2: use a define for the maximum sample count
    v3: also test odd sample counts (r300 supports MS3)
    
    While multisample renderbuffers are supported by mesa, MS visuals
    are not, so we need a way to tell dri/st not to advertise them even
    if the gallium driver does support multisampled surfaces.
    
    Otherwise applications selecting these non-functional visuals would
    run into trouble ...
    
    Reviewed-by: Brian Paul <brianp@vmware.com>

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