Bug 9576

Summary: Screen corruption at 24-bit color depth on radeon
Product: Mesa Reporter: David Brigada <brigad>
Component: Drivers/DRI/r200Assignee: Default DRI bug account <dri-devel>
Status: NEW --- QA Contact:
Severity: normal    
Priority: high CC: tomwolfe
Version: unspecified   
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:

Description David Brigada 2007-01-08 17:19:24 UTC 
I have an ATI Radeon Mobility 9000 (r250, ATI Mobility M9, 32 MB of RAM).  The
radeon DRI driver causes screen corruption when I use a 24-bit color depth with
AIGLX and Beryl.  Reducing the color depth to 16 bits fixes this.  Under 24-bit
depth, the screen behaves partially like it will only render in a 1024x1024
block.  Windows drawn outside the area do not get properly erased, etc.

See also http://www.rpi.edu/~brigad/ss1.png for a screenshot, and
http://bugs.beryl-project.org/ticket/177 for more information on the bug, as
researched in context of Beryl.
Comment 1 Michel Dänzer 2007-01-08 23:01:43 UTC 
This could be due to the texture size limit (glxinfo -l|grep TEXTURE_SIZE). If
so, creating an /etc/drirc file with

<option name="allow_large_textures" value="2" />

should help.
Comment 2 David Brigada 2007-01-09 18:40:55 UTC 
(In reply to comment #1)
> <option name="allow_large_textures" value="2" />

Thanks for the feedback.  The texture size limit is indeed 1024.  When I make
this change, performance of windows beyond a certain point (I haven't figured
out exactly the criteria yet, but it always happens to fullscreen windows) drops
dramatically when in 24-bit mode, but not in 16-bit mode.  Is this a hardware
limitation, a driver limitation, a bug, or what?
Comment 3 Michel Dänzer 2007-01-10 02:04:05 UTC 
The bad performance is most likely due to texture thrashing. The X log file
should say how much video RAM is available for textures; a 1400x1050x32 texture
uses up at least 5.6 MB. If that's the problem, you may be able to alleviate it
somewhat with Option "FBTexPercent".
Comment 4 Timo Jyrinki 2007-02-10 05:49:49 UTC 
Confirming the observations. I'm not sure about the details, but if Beryl eg. really uses 1400x1050x32bit texture for each of the desktops (sides of the cube), it's no wonder it slows down with 32MB video RAM I also have on my Mobility 9000. It does that too with 1024x768, but to a little less extend.

But going back to the original bug, should the 2048x2048 textures be allowed by default these days? I don't see anything wrong with those, and at least all the r200+ hardware supports those (probably even r100?). People do have r200 cards in their desktop computers with even 256MB RAM, so they'd probably like to use >1024x768 resolution with Beryl.
Comment 5 Michel Dänzer 2007-02-13 00:47:03 UTC 
Reassigning to the r200 driver, it might make sense to advertise the hardware texture size limit by default these days.
Comment 6 Thomas Wolfe 2007-02-13 05:52:33 UTC 
*** Bug 9963 has been marked as a duplicate of this bug. ***
Comment 7 chemtech 2013-03-15 14:27:36 UTC 
David Brigada
Do you still experience this issue with newer soft ?
Please check the status of your issue.

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