Bug 61349 - [r300g, bisected] piglit rgtc-teximage-01 fails
Summary: [r300g, bisected] piglit rgtc-teximage-01 fails
Status: RESOLVED NOTABUG
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Gallium/r300 (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
Whiteboard:
Keywords: regression
Depends on:
Blocks:
 
Reported: 2013-02-23 14:40 UTC by Pavel Ondračka
Modified: 2013-11-02 22:41 UTC (History)
0 users

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Description Pavel Ondračka 2013-02-23 14:40:52 UTC
./bin/rgtc-teximage-01 -auto
r300: DRM version: 2.24.0, Name: ATI RV530, ID: 0x71c5, GB: 1, Z: 2
r300: GART size: 509 MB, VRAM size: 256 MB
r300: AA compression RAM: YES, Z compression RAM: YES, HiZ RAM: YES
Got bad R channel reading back 0x8dbb as 0x1908
Got bad R channel reading back 0x8dbc as 0x1908
PIGLIT: {'result': 'fail' }

first bad commit:
commit ea63491629f48099371f725e7c3779f2982d7a52
Author: Marek Olšák <maraeo@gmail.com>
Date:   Thu Feb 7 04:36:33 2013 +0100

    st/mesa: accelerate glGetTexImage for all formats using a blit
    
    This commit allows using glGetTexImage during rendering and still
    maintain interactive framerates.
    
    This improves performance of WarCraft 3 under Wine. The framerate is improved
    from 25 fps to 39 fps in the main menu, and from 0.5 fps to 32 fps in the game.
    
    v2: fix choosing the format for decompression

GPU:RV530
Mesa: 2fa9e4c97cd7580010a8aa2eb3026e8f2bdb0035
Kernel: 3.7.3-101.fc17.i686
Comment 1 Marek Olšák 2013-02-23 21:03:29 UTC
RGTC1 texturing uses only 4 bits of precision in R500, which can cause some piglit failures. If you run the test, you'll see how the precision affects the filtered texture. If it's not completely wrong, let's just say this is a hardware limitation.
Comment 2 Pavel Ondračka 2013-02-23 23:28:43 UTC
(In reply to comment #1)
> RGTC1 texturing uses only 4 bits of precision in R500, which can cause some
> piglit failures. If you run the test, you'll see how the precision affects
> the filtered texture. If it's not completely wrong, let's just say this is a
> hardware limitation.

Yeah, the pictures before and after patch looks almost similar, so probably indeed a precision bug, dunno why it passed before though.
Comment 3 Marek Olšák 2013-11-02 22:40:58 UTC
Closing, because it's a hardware limitation.


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