The chipset works perfectly with latest XFree 4.2.0 release. If you use
the cvs version you also have acceleration (I can watch DVD's smoothly).

Here you are my config file (I use redhat rawhide XFree). Enjoy. 


---------------------------------------------------------------
# XFree86 4.2.0 configuration generated by Xconfigurator 4.10.7

Section "ServerLayout"
	Identifier "XFree86 Configured"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "MouseUSB" "SendCoreEvents"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

# Red Hat Linux 6.0 and later use the xfs font server for improved
# interactive performance

Section "Files"
	FontPath "unix/:7100"
EndSection

# Module loading section

Section "Module"
	Load  "dbe"		# Double-buffering
	Load  "GLcore"		# OpenGL support
	Load  "dri"		# Direct rendering infrastructure
	Load  "glx"		# OpenGL X protocol interface
	Load  "extmod"		# Misc. required extensions
	Load  "v4l"		# Video4Linux
	# Load  "record"	# X event recorder
	# You only need the following two modules if you do not use xfs.
	# Load  "freetype"	 # TrueType font handler
	# Load  "type1"		# Adobe Type 1 font handler
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "keyboard"
	Option      "XkbLayout"	"us"
EndSection


Section "InputDevice"
	Identifier	"Mouse0"
	Driver		"mouse"
	Option		"Device"		"/dev/psaux"
	Option		"Protocol"		"IMPS/2"
	Option		"Emulate3Buttons"	"on"
	Option		"ZAxisMapping"		"4 5"
EndSection


Section "InputDevice"
	Identifier	"MouseUSB"
	Driver		"mouse"
	Option		"Device"		"/dev/input/mice"
	Option		"Protocol"		"IMPS/2"
	Option		"Emulate3Buttons"	"no"
	Option		"ZAxisMapping"		"4 5"
EndSection


Section "Monitor"
	Identifier "Generic Laptop Display Panel 1024x768"
	VendorName "Unknown"
	ModelName  "Unknown"
	HorizSync 31.5-48.5
	VertRefresh 40-70
	Option "dpms"
EndSection

Section "Device"
	Identifier "Trident CyberBladeXPm"
	Driver "trident"
	chipset "cyberbladeXPAi1"
        Option  "CyberStretch"
        Option  "ShadowFB" "on"
        VideoRam  16384
        VendorName  "Toshiba"
        BoardName  "CyberBlade XP"
        #BusId             "PCI:1:0:0"
EndSection

Section "Device"
	Identifier "VesaDevice"
	Driver "vesa"
	Option "shadowfb"
EndSection

Section "Device"
	Identifier "Linux Frame Buffer"
	Driver "fbdev"
	BoardName "Unknown"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device "Trident CyberBladeXPm"
#	Device "VesaDevice"
	Monitor "Generic Laptop Display Panel 1024x768"
	DefaultDepth 16
	Subsection "Display"
		Depth 24
		Modes "1024x768"
#		Modes "1600x1200" "1280x1024" "1152x864" "1024x768"
	EndSubSection
	Subsection "Display"
		Depth 16
		Modes "1024x768"
#		Modes "1600x1200" "1280x1024" "1152x864" "1024x768"
	EndSubSection
EndSection

Section "DRI"
	Mode 0666
EndSection