Xorg totally unusable with KMS and new Xorg on Sandy Bridge system: how to undo

[Thomas Mueller]

Thomas Mueller writes:

>  I built the newer Xorg and it falls flat: goes to a nongraphic
>  screen that is blank except for a rectangular cursor in the upper
>  left corner, and now I want to get back to the earlier Xorg.
>
>  System is Intel Sandy Bridge with i7 CPU.

Robert Huff responds:

>         You don't mention your graphics chip explicitly, but building
> libdrm with the KMS option was enough to prevent X from starting on
> a Radeon HD 3300.  ("Experimental", indeed!  :-)
>         Other will be able to help more if you could post the contents
> of "/var/log/Xorg.0.log" and your xorg.conf file.

My /var/log/Xorg.0.log has 0 bytes!

To Andrey Fesenko <f0andrey at gmail.com>:

Were you able to start X with 

# cat /etc/make.conf
WITH_NEW_XORG=true
WITH_KMS=true

X.Org X Server 1.10.6
Release Date: 2012-02-10
intel(0): Integrated Graphics Chipset: Intel(R) Sandybridge Mobile (GT2+)

(end of quote from Andrey Fesenko)

Xorg -configure (by root) produced an error message, failed but left a file
Xorg.conf.new


Section "ServerLayout"
	Identifier     "X.org Configured"
	Screen      0  "Screen0" 0 0
	Screen      1  "Screen1" RightOf "Screen0"
	Screen      2  "Screen2" RightOf "Screen1"
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	ModulePath   "/usr/local/lib/xorg/modules"
	FontPath     "/usr/local/lib/X11/fonts/misc/"
	FontPath     "/usr/local/lib/X11/fonts/TTF/"
	FontPath     "/usr/local/lib/X11/fonts/OTF/"
	FontPath     "/usr/local/lib/X11/fonts/Type1/"
	FontPath     "/usr/local/lib/X11/fonts/100dpi/"
	FontPath     "/usr/local/lib/X11/fonts/75dpi/"
EndSection

Section "Module"
	Load  "extmod"
	Load  "record"
	Load  "dbe"
	Load  "dri"
	Load  "dri2"
	Load  "glx"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto"
	Option	    "Device" "/dev/sysmouse"
	Option	    "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
EndSection

Section "Monitor"
	Identifier   "Monitor1"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
EndSection

Section "Monitor"
	Identifier   "Monitor2"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "DRI"                	# [<bool>]
        #Option     "ColorKey"           	# <i>
        #Option     "VideoKey"           	# <i>
        #Option     "FallbackDebug"      	# [<bool>]
        #Option     "Tiling"             	# [<bool>]
        #Option     "LinearFramebuffer"  	# [<bool>]
        #Option     "Shadow"             	# [<bool>]
        #Option     "SwapbuffersWait"    	# [<bool>]
        #Option     "TripleBuffer"       	# [<bool>]
        #Option     "XvMC"               	# [<bool>]
        #Option     "XvPreferOverlay"    	# [<bool>]
        #Option     "DebugFlushBatches"  	# [<bool>]
        #Option     "DebugFlushCaches"   	# [<bool>]
        #Option     "DebugWait"          	# [<bool>]
        #Option     "HotPlug"            	# [<bool>]
        #Option     "RelaxedFencing"     	# [<bool>]
	Identifier  "Card0"
	Driver      "intel"
	BusID       "PCI:0:2:0"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "ShadowFB"           	# [<bool>]
        #Option     "Rotate"             	# <str>
        #Option     "fbdev"              	# <str>
        #Option     "debug"              	# [<bool>]
	Identifier  "Card1"
	Driver      "fbdev"
	BusID       "PCI:0:2:0"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "ShadowFB"           	# [<bool>]
        #Option     "DefaultRefresh"     	# [<bool>]
        #Option     "ModeSetClearScreen" 	# [<bool>]
	Identifier  "Card2"
	Driver      "vesa"
	BusID       "PCI:0:2:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection

Section "Screen"
	Identifier "Screen1"
	Device     "Card1"
	Monitor    "Monitor1"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection

Section "Screen"
	Identifier "Screen2"
	Device     "Card2"
	Monitor    "Monitor2"
	SubSection "Display"
		Viewport   0 0
		Depth     1
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     4
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     8
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     15
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     16
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection


Tom