Help! Screen resolution problem with Via P4M890 S3 Unichrome Pro

[gurogarry]

Hello. Linux/Ubuntu newbie here. I am running Ubuntu 8.10 with a Via Technologies P4M890 S3 Unichrome Pro (Rev 01) graphics chipset. When I first installed Ubuntu, it started correctly with 1024x768 screen resolution, with options for higher resolutions. Everything was fine for about a month.

Then one day while shutting down, the colors of the logo weren't correct. When I rebooted, the computer came up in 800x600 resolution and only give options for 800x600 and 640x480.

I've tried booting with the LiveCD and a complete reinstall. Both gave the same results. I've spent hours searching through this forum for an answer, and trying out the solutions I sort of understand, but nothing has worked so far.

Can someone please help me?

Thx,

G.

[overdrank]

HI and have you tried booting into recovery mode and using the xfix option. Recovery mode is usually the second choice from the grub. Then you can choose the xfix option. Then you should be given the choice of booting normally after the configuration of you x is complete.

[gurogarry]

Tried it. No go. Same problem. Any other suggestions?

[overdrank]

Tried it. No go. Same problem. Any other suggestions?

The amount of memory shared with the graphics in bios. If you can adjust this it may help.

[gurogarry]

OK. I increased the shared memory from 64M to 128MB, but still no change. Also, I have a dual boot setup with XP, and the XP works just fine in 1280x768 mode.

[gurogarry]

I'm still not getting anywhere with this and am still stuck in 800x600 resolution. Today I tried following the directions at https://help.ubuntu.com/community/OpenChrome.

I got as far as "...change Section "Device" Driver "vesa" to Driver "openchrome".

This is what I got:

Section "Device"
Identifier "Configured Video Device"
EndSection

Section "Monitor"
Identifier "Configured Monitor"
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
EndSection

It's not showing any drivers. I also tried running sudo dpkg-reconfigure -phigh xserver-xorg as mentioned, but all I got was:

xserver-xorg postinst warning: overwriting possibly-customised configuration file; backup in /etc/X11/xorg.conf.20090222175002

...and was returned to the command prompt.

Can someone please help me?

Thx,

Garry

[amylase]

Hi Gary

I'm using

VGA compatible controller: VIA Technologies, Inc. KM400/KN400/P4M800 [S3 UniChrome] (rev 01)

with exact same problem as you. I went as far as editing the file and like you, I couldn't find Driver "vesa" part.

Did you manage to fix your problem in the end? If so, how did you do it?

Thanks a lot.

[MegaJim]

I've got this chip on my old Laptop. There seems to be a problem with versions of Ubuntu after 7.10 not properly detecting the resolution of any devices connected to a KM400/P4M800 Unichrome, and 2d acceleration is also causing hard crashes.

The simple solution is to manually specificy the chipset in xorg.conf, disabling acceleration and adding some lines for resolutions.

Here is my xorg.conf from my Acer 1360

#/etc/X11/xorg.conf

Section "Device"
	Identifier	"Configured Video Device"
	Driver		"openchrome"
	Option		"XaaNoImageWriteRect"
EndSection

Section "Monitor"
	Identifier	"Configured Monitor"
EndSection

Section "Screen"
	Identifier	"Default Screen"
	Monitor		"Configured Monitor"
	Device		"Configured Video Device"
	DefaultDepth	24
	SubSection "Display"
		Modes	"800x600" "1024x768"
	EndSubSection
EndSection

[Junkieman]

Hi, I'm not sure this will work, but it's worth a try yeah?


Firstly, backup your files:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.bak

Edit xorg.conf, under the "Screen" Section add another entry for your res, for example 1024x768

sudo gedit /etc/X11/xorg.conf

New lines added are red:

(snip)...
Section "Screen"
    Identifier    "Default Screen"
    Device        "Intel Corporation Express Graphics Controller"
    Monitor        "Generic Monitor"
    DefaultDepth    24
    SubSection "Display"
        Modes        "800x480"
        Modes        "1024x768"
    EndSubSection
EndSection
... (snip)

Save the file and restart the X Desktop (CTRL+ALT+BACKSPACE), and check if the res is now available in the Screen Resolution dialog.

[Agent.Logic_]

Junkieman's solution will fix it 99.99% of the time. I had to tinker with the xorg.conf file myself to fix my display issues. VIA chipsets are gaining a reputation of screwing up displays on systems running linux, and they have very little official support for linux video drivers. Those of us with hardware from this manufacturer are being discriminated against.

Should Junkieman's solution not fix it, try downloading the "xserver-xorg-video-openchrome" video driver from Synaptic, and then try editing the xorg.conf file as mentioned in his solution. Do not forget to add the line:

Driver "openchrome"

under Section "Device". One downside to this driver is that there is little to no support for 3D acceleration, but from experience, I can say that this driver is the most stable and reliable of all drivers for VIA chipsets. Good luck!