Help: resolution problem with Radeon 9250 + Linux + X-6.8.2

[Jeremy Henty]

I've been happily using X.org 6.8.2 (with DRI) on Linux 2.6.17.13 ,
Radeon 9250 , 1280x1024 resolution.  But when I upgrade to Linux
2.6.18 it starts in 640x512.  I can't Ctrl-Alt-[+-] to anything else.

After taking this to the Linux From Scratch lists I've tried: 

 * disabling EDID in the kernel .config (this option only appeared in
   Linux 2.6.18)
 * All 2x2 combinations of True/False for DDCMode and IgnoreEDID in
   xorg.conf .
 * Enabling I2C in the kernel .config .
 * Specifying the mode in xorg.conf .

Nothing makes any difference - under Linux 2.6.17.13 I get 1280x1024
without problems, under Linux 2.6.18 I can't get anything except
640x512 .  My xorg.conf (attached) is pretty minimal.  I haven't tried
writing mode lines yet.

Any suggestions?

(I'm trying to upgrade to X 6.9.0 but I'm having build problems.  The
monitor is an IIyama Vision Master 450.)

Thanks, 

Jeremy Henty 
-------------- next part --------------
Section "ServerLayout"
	Identifier     "X.org Configured"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	RgbPath      "/usr/X11R6/lib/X11/rgb"
	ModulePath   "/usr/X11R6/lib/modules"
	FontPath     "/usr/share/fonts/misc/"
	FontPath     "/usr/share/fonts/TTF/"
	FontPath     "/usr/share/fonts/Type1/"
	FontPath     "/usr/share/fonts/CID/"
	FontPath     "/usr/share/fonts/75dpi/"
	FontPath     "/usr/share/fonts/100dpi/"
EndSection

Section "Module"
	Load  "extmod"
	Load  "glx"
	Load  "dri"
	Load  "dbe"
	Load  "record"
	Load  "xtrap"
	Load  "type1"
	Load  "freetype"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option      "XkbLayout" "gb"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto"
	Option	    "Device" "/dev/mouse"
EndSection

Section "Monitor"
	#DisplaySize	  360   270	# mm
	Identifier   "Monitor0"
	VendorName   "IVM"
	ModelName    "1900"
	Option	    "DPMS"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
        ### [arg]: arg optional
        #Option     "NoAccel"            	# [<bool>]
        #Option     "SWcursor"           	# [<bool>]
        #Option     "Dac6Bit"            	# [<bool>]
        #Option     "Dac8Bit"            	# [<bool>]
        #Option     "BusType"            	# [<str>]
        #Option     "CPPIOMode"          	# [<bool>]
        #Option     "CPusecTimeout"      	# <i>
        #Option     "AGPMode"            	# <i>
        #Option     "AGPFastWrite"       	# [<bool>]
        #Option     "AGPSize"            	# <i>
        #Option     "GARTSize"           	# <i>
        #Option     "RingSize"           	# <i>
        #Option     "BufferSize"         	# <i>
        #Option     "EnableDepthMoves"   	# [<bool>]
        #Option     "EnablePageFlip"     	# [<bool>]
        #Option     "NoBackBuffer"       	# [<bool>]
        #Option     "PanelOff"           	# [<bool>]
        #Option     "DDCMode"            	# [<bool>]
        #Option     "DDCMode"            	"True"
        #Option     "DDCMode"            	"False"
        #Option     "MonitorLayout"      	# [<str>]
        #Option     "IgnoreEDID"         	# [<bool>]
        #Option     "IgnoreEDID"         	"True"
        #Option     "IgnoreEDID"         	"False"
        #Option     "UseFBDev"           	# [<bool>]
        #Option     "VideoKey"           	# <i>
        #Option     "MergedFB"           	# [<bool>]
        #Option     "CRT2HSync"          	# [<str>]
        #Option     "CRT2VRefresh"       	# [<str>]
        #Option     "CRT2Position"       	# [<str>]
        #Option     "MetaModes"          	# [<str>]
        #Option     "MergedDPI"          	# [<str>]
        #Option     "NoMergedXinerama"   	# [<bool>]
        #Option     "MergedXineramaCRT2IsScreen0" 	# [<bool>]
        #Option     "DisplayPriority"    	# [<str>]
        #Option     "PanelSize"          	# [<str>]
        #Option     "ForceMinDotClock"   	# <freq>
        #Option     "RenderAccel"        	# [<bool>]
        #Option     "SubPixelOrder"      	# [<str>]
        #Option     "ShowCache"          	# [<bool>]
        #Option     "DynamicClocks"      	# [<bool>]
	Identifier  "Card0"
	Driver      "ati"
	VendorName  "ATI Technologies Inc"
	BoardName   "Unknown Board"
	BusID       "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	DefaultDepth 16
	SubSection "Display"
		Depth 16
		Viewport 0 0
		Modes   "1280x1024"
	EndSubSection
EndSection

Section "DRI"
	Mode 0666
EndSection