Brightness control on PowerBook G4 1.33GHz, 12", GeForce FX Go5200

[Zoltan Nagy <nagyz@physics.uoregon.edu>]

Hi,

I jut got a new powerbook and I installed Debian/Sid with the most
recent version of the distributed Linux kernel (2.6.8). It works fine
but I cannot control the screen brightness. I tried to configure the
framebuffer in the XF86Configure-4 (please find attached my
configuration file) file but the X system gives the following error:

(II) Module fbdevhw: vendor="The XFree86 Project"
        compiled for 4.3.0.1, module version = 0.0.2
        ABI class: XFree86 Video Driver, version 0.6
(WW) open /dev/fb1: No such file or directory
(WW) open /dev/fb2: No such file or directory
(WW) open /dev/fb3: No such file or directory
(WW) open /dev/fb4: No such file or directory
(WW) open /dev/fb5: No such file or directory
(WW) open /dev/fb6: No such file or directory
(WW) open /dev/fb7: No such file or directory
(EE) Unable to find a valid framebuffer device
(EE) NV(0): Failed to open framebuffer device, consult warnings and/or
errors above for possible reasons
        (you may have to look at the server log to see warnings)

I didn't load the rivafb module. It use the offb driver. 

Thanks your help,
Zoltan

# XF86Config-4 (XFree86 X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the XF86Config-4 manual page.
# (Type "man XF86Config-4" at the shell prompt.)
#
# This file is automatically updated on xserver-xfree86 package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xfree86
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following commands as root:
#
#   cp /etc/X11/XF86Config-4 /etc/X11/XF86Config-4.custom
#   md5sum /etc/X11/XF86Config-4 >/var/lib/xfree86/XF86Config-4.md5sum
#   dpkg-reconfigure xserver-xfree86

Section "Files"
	FontPath	"unix/:7100"			# local font server
	# if the local font server has problems, we can fall back on these
	FontPath	"/usr/lib/X11/fonts/misc"
	FontPath	"/usr/lib/X11/fonts/cyrillic"
	FontPath	"/usr/lib/X11/fonts/100dpi/:unscaled"
	FontPath	"/usr/lib/X11/fonts/75dpi/:unscaled"
	FontPath	"/usr/lib/X11/fonts/Type1"
	FontPath	"/usr/lib/X11/fonts/CID"
	FontPath	"/usr/lib/X11/fonts/Speedo"
	FontPath	"/usr/lib/X11/fonts/100dpi"
	FontPath	"/usr/lib/X11/fonts/75dpi"
EndSection

Section "Module"
	Load	"GLcore"
	Load	"bitmap"
	Load	"dbe"
	Load	"ddc"
	Load	"dri"
	Load	"extmod"
	Load	"freetype"
	Load	"glx"
	Load	"int10"
	Load	"record"
	Load	"speedo"
	Load	"type1"
	Load	"vbe"
	Load	"xtt"
EndSection

Section "InputDevice"
	Identifier	"Generic Keyboard"
	Driver		"keyboard"
	Option		"CoreKeyboard"
	Option		"XkbRules"	"xfree86"
	Option		"XkbModel"	"macintosh"
	Option		"XkbLayout"	"gb"
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	"Generic Video Card"
	Driver		"nv"
	Option 		"FlatPanel"	"true"
	Option    	"UseFBDev"	"true"
	BusID      	"PCI:0:16:0"
	Option		"fbdev"		"/dev/fb0"
EndSection

Section "Monitor"
	Identifier	"Generic Monitor"
	HorizSync	30-100
	VertRefresh	50-120
	Option		"DPMS"
	UseModes	"Generic Modes"
EndSection

Section "Modes"
	Identifier	"Generic Modes"
	Mode "1024x768"
    	# D: 100.000 MHz, H: 93.985 kHz, V: 116.318 Hz
    	DotClock 100.001
    	HTimings 1024 1040 1048 1064
    	VTimings 768 784 792 808
    	Flags    "-HSync" "-VSync"
	EndMode
EndSection


Section "Screen"
	Identifier	"Default Screen"
	Device		"Generic Video Card"
	Monitor		"Generic Monitor"
	DefaultDepth	24
	SubSection "Display"
		Depth		1
		Modes		"1024x768"
	EndSubSection
	SubSection "Display"
		Depth		4
		Modes		"1024x768"
	EndSubSection
	SubSection "Display"
		Depth		8
		Modes		"1024x768"
	EndSubSection
	SubSection "Display"
		Depth		15
		Modes		"1024x768"
	EndSubSection
	SubSection "Display"
		Depth		16
		Modes		"1024x768"
	EndSubSection
	SubSection "Display"
		Depth		24
		Modes		"1024x768"
	EndSubSection
EndSection

Section "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
EndSection

Section "DRI"
	Mode	0666
EndSection