Bug 34378

Summary:	st/mesa: 2a904fd6a0cb80eec6dec2bae07fd8778b04caf3 breaks sauerbraten
Product:	Mesa	Reporter:	Fabio Pedretti <pedretti.fabio>
Component:	Mesa core	Assignee:	Marek Olšák <maraeo>
Status:	RESOLVED FIXED	QA Contact:
Severity:	minor
Priority:	low	CC:	nobled
Version:	git
Hardware:	x86 (IA32)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	workaround

Description Fabio Pedretti 2011-02-17 02:11:18 UTC

Since 2a904fd6a0cb80eec6dec2bae07fd8778b04caf3 sauerbraten shows triangles popping around on some frames. My card:

r300: DRM version: 2.7.0, Name: ATI RV530, ID: 0x71c5, GB: 1, Z: 2
r300: GART size: 509 MB, VRAM size: 256 MB
r300: AA compression: NO, Z compression: NO, HiZ: NO

Comment 1 Brian Paul 2011-02-17 06:31:54 UTC

That commit is also causing problems with Google Earth running in a VM when using the Gallium svga driver.  If this can't be fixed soon, we may have to revert this patch (and the follow-ons).

Assigning to Marek.  Marek, do you have any ideas about what might be going on?

Comment 2 Marek Olšák 2011-02-17 07:28:16 UTC

Created attachment 43487 [details] [review]
workaround

I guess we might be changing vertex attribs somewhere and not updating
the appropriate dirty flags, therefore we can't rely on them for now.
Or maybe we need to make the vertex array state dependent on some other flags too. I have no idea currently.

I have an ugly workaround which fixes sauerbraten. Please see the attached patch. It basically reverts my commit and gives a clue on what's going on.

Comment 3 Marek Olšák 2011-02-18 00:24:07 UTC

Update: This bug only shows up if shaders are used. The fixed-function pipeline is unaffected.

Comment 4 Alexandros Frantzis 2011-02-18 02:55:18 UTC

Commit 2a904fd6a0cb80eec6dec2bae07fd8778b04caf3 also breaks the cairo-gl backend.

FWIW, the attached workaround fixes the problem.

Comment 5 Fabio Pedretti 2011-03-02 01:10:58 UTC

Note that the workaround was applied in:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=bb46eeade3a3eb604aba5c084d1e21942c2fa2ac

Comment 6 Marek Olšák 2011-03-08 14:46:53 UTC

Fixed with commits ef58598c1cf2ac689f67c75b2f477f2c404fce98 and 12fa91b6753dccbd3aa12c570d1f1e55c7dc0582. Closing.

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.