Bug 62830

Summary:	[i965 bisected] Wrong Lightning on Freespace 2 SCP (patch attached)
Product:	Mesa	Reporter:	Joaquín Ignacio Aramendía <samsagax>
Component:	Drivers/DRI/i965	Assignee:	Ian Romanick <idr>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium	Keywords:	regression
Version:	9.1
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	bisect log of the issue Proposed patch to fix the issue.

Description Joaquín Ignacio Aramendía 2013-03-27 17:50:19 UTC

Playing Freespace 2 SCP in Archlinux I've noticed all objects with strange lightning issues. They glow and flash between the normal light and total white.

Hera are 4 pictures (http://imgur.com/6FRzz5T,aIrDuFo,oUUqIia,s01MP7Y#0). The first three were taken rendering with the integrated Intel chip. Notice the "sun-sided" part of the ship. The fourth was taken rendering the exact same game with the dedicated Nvidia GPU (through bumblebee with nvidia proprietary driver).

I couldn't test it with nouveau driver because the game crashes X with a segfault on libnouveau_drv (probably due to s3tc texture, I'm not sure).

This rendering issue is also present in other applications (gtkglext one, made by me), I can provide it if it's necessary.

Chipset: Integrated Graphics Chipset: Intel(R) Arrandale
architecture: x86_64
xf86-video-intel: 2.21.5-1
xorg-server: 1.14.0-2
mesa: 9.1.1-1
libdrm: 2.4.42-1
kernel: 3.8.4-1-ARCH

Steps to reproduce: enter a the game, enter a mission, just look around for any ship.

Comment 1 Joaquín Ignacio Aramendía 2013-03-27 17:54:08 UTC

The trace file is 111Mb in size. How could I upload the relevant bits?

Comment 2 Joaquín Ignacio Aramendía 2013-03-27 19:51:31 UTC

Ok. Uploaded to Dropbox. As I have no idea how to trim it properly. http://dl.dropbox.com/u/101701104/fs2_open.trace

Comment 3 Joaquín Ignacio Aramendía 2013-03-27 20:53:54 UTC

It's a regression. Works fine with mesa 8.0.4. Will try to bisect it.

Comment 4 Joaquín Ignacio Aramendía 2013-03-28 00:07:29 UTC

Bisecting between 9.2-devel (current master) and mesa-8.0.4 tag gave me this. Hope is helpful


The merge base 6fe42b603d0ec9e13a8b7d6c46c6d89da3a6a614 is bad.
This means the bug has been fixed between 6fe42b603d0ec9e13a8b7d6c46c6d89da3a6a614 and [6fe42b603d0ec9e13a8b7d6c46c6d89da3a6a614 c1f4867c89adb1a6b19d66ec8ad146115909f0a7].

Comment 5 Joaquín Ignacio Aramendía 2013-03-28 19:16:21 UTC

Created attachment 77170 [details]
bisect log of the issue

Well I hit the first bad commit by a bisection (I'm attaching the bisect log):

7426d9d7699452f15f3288e781e1791d8d00a64a is the first bad commit
commit 7426d9d7699452f15f3288e781e1791d8d00a64a
Author: Olivier Galibert <galibert@pobox.com>
Date:   Thu Jul 19 22:00:16 2012 +0200

    i965/fs: Fix the FS inputs setup when some SF outputs aren't used in the FS.
    
    If there was an edge flag or a two-side-color pair present, we'd end up
    mismatched and read values from earlier in the VUE for later FS inputs.
    
    v2: Fix regression in gles2conform shaders generating point size. (change by
        anholt)
    
    Signed-off-by: Olivier Galibert <galibert@pobox.com>
    Reviewed-by: Eric Anholt <eric@anholt.net>
    Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
    NOTE: This is a candidate for the 8.0 branch.

:040000 040000 b590ab710e004c4a760b0b7268bd1ad98bc99fdd d0cfb9acec2290d01c6f2e4d1902c66035547aaf M	src

Comment 6 Joaquín Ignacio Aramendía 2013-03-29 06:09:08 UTC

Created attachment 77185 [details] [review]
Proposed patch to fix the issue.

The patch attached fixed the issue for me. Apply on top of master (ee624ced364bfd2f896809874ef3a808a11c5ecf).

Hope it helps.

Comment 7 Eric Anholt 2013-03-31 19:49:37 UTC

commit 0967c362bf378b7415c30ca6d9523d3b2a3a7f5d
Author: Eric Anholt <eric@anholt.net>
Date:   Fri Mar 29 00:26:07 2013 -0700

    i965: Fix an inconsistency inb the VUE map with gl_ClipVertex on gen4/5.

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