Comment 7 for bug 47775

I was trying a new xorg.conf file I found on the net that utilizes a MergedFB
setup (http://mg.pov.lt/xorg.conf).

However, when switching through the metamodes the system always freezes
completely and without any chance to save any error log message (even SysRQ
don´t work).

The metamodes are "1024x768-1280x1024 1024x768-1024x768 10
24x768+1280x1024 1280x1024 1024x768 800x600 640x480".

If I am not mistaken, the freeze happens when switching to clone mode, that is
from "1024x768+1280x1024" to "1280x1024" (with ALT-CTRL-NUM+) or from
"1024x768-1280x1024" to "640x480" (with ALT-CTRL-NUM-).

Here is the xorg.conf:

Section "Files"
 FontPath "/usr/share/X11/fonts/misc"
## FontPath "/usr/share/X11/fonts/cyrillic"
 FontPath "/usr/share/X11/fonts/100dpi/:unscaled"
 FontPath "/usr/share/X11/fonts/75dpi/:unscaled"
 FontPath "/usr/share/X11/fonts/Type1"
 FontPath "/usr/share/X11/fonts/CID"
 FontPath "/usr/share/X11/fonts/100dpi"
 FontPath "/usr/share/X11/fonts/75dpi"
        # paths to defoma fonts
 FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
 FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/CID"
EndSection

Section "Module"
 Load "GLcore"
 Load "bitmap"
 Load "ddc"
 Load "dri"
 Load "extmod"
 Load "freetype"
 Load "glx"
 Load "int10"
 Load "type1"
 Load "vbe"
EndSection

Section "InputDevice"
 Identifier "Generic Keyboard"
 Driver "kbd"
 Option "CoreKeyboard"
 Option "XkbRules" "xorg"
 Option "XkbModel" "pc105"
 Option "XkbLayout" "us"
EndSection

Section "InputDevice"
 Identifier "Configured Mouse"
 Driver "mouse"
 Option "CorePointer"
 Option "Device" "/dev/input/mice"
 Option "Protocol" "ImPS/2"
 Option "Emulate3Buttons" "true"
 Option "ZAxisMapping" "4 5"
EndSection

Section "Device"
 Identifier "MergedFB2 ATI Technologies, Inc. Radeon Mobility M6 LY"
 Driver "ati"
 BusID "PCI:1:0:0"
 Option "DynamicClocks" "on"
 Option "MergedFB" "true"
 Option "CRT2Position" "RightOf"
    # This allows X to use MergedFB if the external monitor is not connected
    # when I start X. The ranges are taken from DDC values of the CTX monitor
    # I use at the office; as listed in Xorg.log.
 Option "CRT2HSync" "30-81"
 Option "CRT2VRefresh" "56-76"
    # The next line lets me switch between dual-head and several clone modes
    # of varying resolutions with xrandr.
 Option "MetaModes" "1024x768-1280x1024 1024x768-1024x768 1024x768+1280x1024
1280x1024 1024x768 800x600 640x480"
    # A newer version of the radeon driver has an option that disables vertical
    # scrolling for the 1024x768 part.
 Option "MergedNonRectangular" "true"
    # In 1024x768-1280x1024 mode the DPI is correct (100), but in all other
    # modes it is weird. Try to override
 Option "MergedDPI" "100 100"
EndSection

Section "Device"
 Identifier "Screen0 ATI Technologies, Inc. Radeon Mobility M6 LY"
 Driver "ati"
 BusID "PCI:1:0:0"
 Option "DynamicClocks" "on"
 Screen 0
EndSection

Section "Device"
 Identifier "Screen1 ATI Technologies, Inc. Radeon Mobility M6 LY"
 Driver "ati"
 BusID "PCI:1:0:0"
 Option "DynamicClocks" "on"
 Screen 1
EndSection

Section "Monitor"
 Identifier "Generic Monitor"
 Option "DPMS"
EndSection

Section "Monitor"
 Identifier "Second Monitor"
 Option "DPMS"
EndSection

Section "Screen"
 Identifier "MergedFB2 Screen"
 Device "MergedFB2 ATI Technologies, Inc. Radeon Mobility M6 LY"
 Monitor "Generic Monitor"
 DefaultDepth 24
 SubSection "Display"
  Depth 24
  Modes "1280x1024" "1024x768"
 EndSubSection
EndSection

Section "ServerLayout"
 Identifier "MergedFB2Layout"
 Screen "MergedFB2 Screen"
 InputDevice "Generic Keyboard"
 InputDevice "Configured Mouse"
EndSection

Section "DRI"
 Mode 0666
EndSection

Section "ServerFlags"
   Option "DefaultServerLayout" "MergedFB2Layout"
EndSection

The computer is a IBM Thinkpad X31, Debian SID, Kernel 2.6.16, xorg 7.0.20,
xserver-xorg-video-ati-6.5.0beta as well as xserver-xorg-video-ati-6.4.2.

It doesn´t matter whether XAA or EXA is used.

Best regards,

Michael