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dWolf

Member

Registered: 2009-03-04

Posts: 11

How to change xorg preferred resolution?

I'm using ati x550 (rv370) with KMS. My KMS default resolution is 1024x768 (I set it with kernel's video option) but when I start xorg the default resolution is changed to 800x600 (with no xorg.conf).
xrandr gives this:

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
VGA-0 connected 1024x768+0+0 (normal left inverted right x axis y axis) 267mm x 200mm
   800x600        85.1 +   72.2     75.0     60.3     56.2  
   1024x768       60.0* 
   832x624        74.6  
   640x480        85.0     72.8     75.0     66.7     60.0  
   720x400        87.8     70.1  
DVI-0 disconnected (normal left inverted right x axis y axis)
S-video disconnected (normal left inverted right x axis y axis)

Here I switched to 1024x768 manually because I can't use gnome at lower resolution.
Is that some kind of bug? Is there some way to change the preferred video mode?

Last edited by dWolf (2010-06-29 11:29:03)

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: How to change xorg preferred resolution?

> My KMS default resolution is 1024x768 (I set it with kernel's video option)
Are you sure kernel's video options work w/ KMS?

dWolf

Member

Registered: 2009-03-04

Posts: 11

Re: How to change xorg preferred resolution?

Yes I'm sure. There is no glitches when xorg is starting and Xorg.0.log says I'm using KMS.

...
[    21.771] (II) [KMS] Kernel modesetting enabled.
...

Btw I have radeon.modeset=1 in menu.lst

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: How to change xorg preferred resolution?

What happens if you remove the video options?

dWolf

Member

Registered: 2009-03-04

Posts: 11

Re: How to change xorg preferred resolution?

I think it uses 800x600 for console mode when no video option is applied. I found something interesting searching trough Xorg.0.log:

[    21.968] (II) RADEON(0): Printing probed modes for output VGA-0
[    21.968] (II) RADEON(0): Modeline "800x600"x85.1   56.25  800 832 896 1048  600 601 604 631 +hsync +vsync (53.7 kHz)
[    21.968] (II) RADEON(0): Modeline "1024x768"x60.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz)
[    21.968] (II) RADEON(0): Modeline "832x624"x74.6   57.28  832 864 928 1152  624 625 628 667 -hsync -vsync (49.7 kHz)
[    21.968] (II) RADEON(0): Modeline "800x600"x72.2   50.00  800 856 976 1040  600 637 643 666 +hsync +vsync (48.1 kHz)

Last edited by dWolf (2010-06-29 12:31:42)

shetland_breeder

Member

From: England

Registered: 2010-05-17

Posts: 67

Website

Re: How to change xorg preferred resolution?

I think you need an xorg.conf file. If everything works without one you are OK, but if not, not.

With one you can specify the modes you want in the Display subsection of the
Screen section. And X seems to choose the first one in the list if there is no monitor attached when you start X (eg if you use a KVM as I do).

Run xorg -configure and edit the file it creates.

Pete

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: How to change xorg preferred resolution?

@ dWolf
Maybe you can add an xrandr command to your .xinit to automatically change the resolution when you start X.