Bug 96435

Summary:	[bisected: 3b4486] Alien: Isolation, shader problems on characters show flickering colors.
Product:	Mesa	Reporter:	Alexandre Demers <alexandre.f.demers>
Component:	Drivers/Gallium/radeonsi	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED INVALID	QA Contact:	Default DRI bug account <dri-devel>
Severity:	normal
Priority:	medium	CC:	bas, maraeo
Version:	git
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Alexandre Demers 2016-06-08 05:32:10 UTC

"Alien: Isolation" began showing some problems related to compute shaders today. Alien, Ripley and any other characters (droids...) have their appearance flickering and showing strange colors. Bisecting gave the following.

3b44864ab794ea487d22499e7e2c42565aaac085 is the first bad commit
commit 3b44864ab794ea487d22499e7e2c42565aaac085
Author: Marek Olšák <marek.olsak@amd.com>
Date:   Fri Jun 3 19:17:46 2016 +0200

    radeonsi: fix images with level > 0
    
    This should fix spec@arb_shader_image_load_store@level.
    
    Broken by:
        Commit: 95c5bbae66af3ca1f805d94f6fe8d8e4ba2c9c43
        radeonsi: set some image descriptor fields at bind time
    
    Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

:040000 040000 48196e8b6f41a823b3ec07e9aa21dd3c01ac7edc e6524187d496af18187effda79adad6b84774f2d M	src

Using latest ddx and drm from git repository, kernel 4.7-rc2 on ArchLinux 64.

Comment 1 Alexandre Demers 2016-06-08 05:43:03 UTC

By the way, using a R9 280X.

Comment 2 Alexandre Demers 2016-06-08 05:53:55 UTC

Well, after playing a bit more, I should say that the culprit commit only intensify the problem (generalize it to all a whole character). Otherwise, prior to that commit, it seems some parts of characters are not rendering correctly. I'm bisecting to identify when and which was the first problematic commit.

Comment 3 Alexandre Demers 2016-06-08 22:17:35 UTC

Well, it seems a combination of both Mesa and kernel triggers this bug. After trying to find a good commit (a commit that I knew was not showing this problem earlier) yesterday, and since I was unable to find one, I thought about the fact that I was now using a 4.7-rc2 kernel since monday. So I just went back to kernel 4.7-rc1 and now I'm able to find a good commit. In fact, even using commit 3b4486 works fine with an 4.7-rc1 kernel.

I'll try to bisect the kernel between 4.7-rc1 and 4.7-rc2 to see if I can find the culprit commit on the kernel side.

Comment 4 Alexandre Demers 2016-06-11 18:09:59 UTC

I'll close it for now since I'm unable to reproduce it with the original setup. If I see it again, I'll reopen it.

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