render error with XAA

[Che-Wei Chang]

As the bug, very poor Xorg performance on various older graphics HW -
XAA solves this, described in the following link:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/363238

I enabled XAA option in xorg.conf. However, I got render errors in
some applications.
1. The system monitor only shows the top left cornor around the GMail
logo in the following picture.
   http://farm3.static.flickr.com/2779/4062950845_ab86ca3dc4_b.jpg

2. With system monitor on the top, when I drag the program, Take
ScreenShot, the screen does not refresh correctly.
   There are several ghost shadow left behind.
   http://farm3.static.flickr.com/2714/4062950949_c12dfaff3e_b.jpg

3. The characters in PCManX are truncated.
   http://farm3.static.flickr.com/2542/4062951027_8715e56332_b.jpg

Following is my xorg.conf, is there any option that can work around this issue?


Section "Screen"
       Identifier      "Configured Screen Device"
       Device  "Configured Video Device"
       SubSection "Display"
               Virtual 2624 1200
       EndSubSection
EndSection

Section "Device"
       Identifier      "Configured Video Device"
       Option "Monitor-LVDS" "T42"
       Option "Monitor-DVI-0" "2007FP"
       Option "RenderAccel" "on"
       Option "AGPMode" "4"
       Option "FBTexPercent" "0"
       Option "AccelMethod" "XAA"
       # Option "AccelDFS" "on"
       # Option "MigrationHeuristic" "smart" # "greedy" works well also
       # Option "XAANoOffscreenPixmaps" "true"
       # Option "EnablePageFlip" "on"
       # Option "EnableDepthMoves" "on"
       # Option "ColorTiling" "on"
EndSection
       # Option "NoAccel" "TRUE"
       # Option "DisplayPriority" "HIGH"

Section "Monitor"
       Identifier "2007FP"
       Modeline     "1600x1200_60.00" 139.800 1600 1640 1672 1864 1200 1201
1204 1250 +hsync +vsync
       Option      "dpms"
       HorizSync       30.0 - 81.0
       VertRefresh     56.0 - 76.0
       Option          "PreferredMode" "1600x1200_60.00"
       # Option          "ReducedBlanking"
       # Option      "DDCMode" "off"
EndSection


Section "Monitor"
       Identifier "T42"
       # Option "RightOf" "2007FP"
EndSection

# Section "Module"
#         Load "glx"
#         Load "dri"
# EndSection

# Section "DRI"
#         Mode 0666
# EndSection