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[Bug 393129] [NEW] Corrupt screen, HP Brio, Matrox G100 (display: NEC LCD1860NX and others)

 

Public bug reported:

Binary package hint: xserver-xorg-video-mga

Corrupt screen, HP Brio, Matrox G100 (display: NEC LCD1860NX and others)

HP Brio, Celeron 300MHz with 256Mb ram
On board Matrox G100 8Mb
NEC LCD1860NX flat screen (native resolution 1280x1024)

I have also tried a CRT display and had identical symptoms,
so I doubt this problem is specific for this screen.

The attached photo shows the display on first booting after
installing Ubuntu 9.04.  It looks similar to a TV that's
lost the horizontal hold, and is also displaced a little to
the right and down.  Although some features can be made out,
the content is shown as if 3 copies are overlaid in vertical
stripes.

The next attached photo shows this more clearly, taken after
logging in blind.  Note how, in the top panel, the time is
visible in 3 places.

I found that Puppy and Mepix do not exhibit this problem.
The next experiment was to take the xorg.conf generated by
the Puppy wizard and reduce it to the following, replacing
the empty /etc/X11/xorg.conf with:

---- start ----
Section "ServerFlags"
    Option "RandR" "on"
EndSection


Section "ServerLayout"
	Identifier     "X.org Configured"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option      "XkbRules" "xorg"
	Option      "XkbModel" "pc102"
	Option      "XkbLayout" "us" #xkeymap0
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto" #mouse0protocol
	Option	    "Device" "/dev/mouse"
	#Option      "Emulate3Buttons"
	#Option      "Emulate3Timeout" "50"
	Option      "ZAxisMapping" "4 5" #scrollwheel
EndSection

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
	HorizSync    30-72
	VertRefresh  50-85
	#UseModes     "Modes0" #monitor0usemodes
	Option      "PreferredMode" "1024x768"
	EndSection
	
Section "Modes"
	Identifier "Modes0"
	#modes0modeline0
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     "ShadowFB"           	# [<bool>]
	#Option     "DefaultRefresh"     	# [<bool>]
	#Option     "ModeSetClearScreen" 	# [<bool>]
	Identifier  "Card0"
	Driver      "vesa" #card0driver
	VendorName  "Matrox Graphics, Inc."
	BoardName   "MGA G100 [Productiva] AGP"
	BusID       "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
    DefaultDepth 16
    Subsection "Display"
        Depth       16
        Modes       "1024x768"
    EndSubsection
EndSection
---- end of xorg.conf ----

This still did not fix the display.  Neither did changing
/etc/gdm/gdm.conf GdmXserverTimeout=10 to 25 (following
advice in bug #319363).  But making both changes gave a
good 1024x768 display.

I downloaded an iso of Karmic alpha2 and installed this.
The symptoms were identical.  However, now the change of
GdmXserverTimeout=10 isn't needed, though the change of
xorg.conf still is.

The G100 8Mb should be able to produce 1280x1024 resolution 
with at least 8-bit colour.  Since this is the native resolution 
of the NEC display, this is what I would prefer.

I'm happy to run any tests, and do complete reinstalls of any
distro.  I also have various other displays available that I
could try.

Though due to other commitments it may take several days for
me to respond.  

I have dumps of the /etc and /var/log trees from most of these
experiments; they're rather large, so you may prefer to ask for
specific files.

In case you're wondering, no, the Brio isn't my regular desktop.
But it's a nice compact little box to take along to LUG meets.
Such machines are often discarded these days, yet are adequate
for disadvantaged people wanting very basic facilities.  This
is likely to be their first exposure to Linux, so it's important
that Ubuntu works for them without intervention.

** Affects: xserver-xorg-video-mga (Ubuntu)
     Importance: Undecided
         Status: New

-- 
Corrupt screen, HP Brio, Matrox G100 (display: NEC LCD1860NX and others)
https://bugs.launchpad.net/bugs/393129
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