[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Using xandr -- Re: problems with system-config-display and crtl-alt-backspace



On Tuesday 05 January 2010 14:21:19 Robert Moskowitz wrote:
> On 01/05/2010 05:39 AM, Marko Vojinovic wrote:
> > Sorry to jump in this thread, but have you tried to use xrandr to set up
> > the resolution you want? That way you don't need to generate xorg.conf,
> > and can convince X to give you any resolution you want (if supported by
> > hardware).
> 
> OK. So I have seen this mention of xandr before so I did a man on it.
> Here is what I see from just xandr and with the xorg.conf:
> 
> Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
> LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis)
> 261mm x 163mm
> 1024x768 60.0*+
> 1280x800 59.8 +
> 800x600 60.3 56.2
> 640x480 59.9

This looks ok, if you are satisfied with 1024x768 for the laptop display. I see 
it is possible for it to do 1280x800, which is its 'native' resolution, I 
guess.

> VGA1 connected (normal left inverted right x axis y axis)
> 800x600 60.3 56.2
> 640x480 59.9

This doesn't look ok. Only these two low resolutions are available for the 
external display, and AFAIK this is always available by assumption. But the 
resolutions of your monitor are not autodetected properly. What kind of 
monitor do you have connected to VGA? If you are sure it can do 1024x768, then 
something is not well with EDID detection. Can you post the 
/var/log/Xorg.0.log, after booting with external monitor connected? There 
should be some info there on what resolutions get autodetected for external 
monitor (and if not, why not). Do you have something physically connected 
between the monitor and computer? A KVM switch, a splitter, maybe a faulty VGA 
extension cable, or such? Or the monitor is too old and doesn't provide EDID 
data?

> Forces to use a 1024x768 mode on an output called VGA:
> xrandr --newmode "1024x768" 63.50 1024 1072 1176 1328 768 771
> 775 798 -hsync +vsync
> xrandr --addmode VGA 1024x768
> xrandr --output VGA --mode 1024x768

Umm, that should be VGA1, not VGA.

Normally there is no need to specify the modeline manually, so the last 
command only should be enough. But it appears your monitor doesn't get 
detected properly, so manually specifying the modeline may be the only 
solution. This is of course easier to put in xorg.conf.

Also, what kind of setup would you like to have? Do you want cloned or 
independent displays? Which goes on the left and which on the right? What 
resolutions?

> This is REALLY better than xorg.conf? In what way?

Ok, I said I jumped in on this thread, maybe I missed something. What are your 
reasons against using xorg.conf in the first place? The difference between 
xorg.conf and xrandr is that the former is being used at boot, while the 
latter is targeted for interactive use. It is also a bit easier on the syntax 
(if your displays are detected correctly). If you have some specific reason for 
not using xorg.conf, you can experiment with various xrandr setups, and once 
you are satisfied, put the resulting command in a script somewhere to be 
executed on login or such.

Post the output of /var/log/Xorg.0.log, so we can see what is the problem with 
autodetection of the external display, and your desired configuration, and then 
we'll see what is the best way to fix it.

HTH, :-)
Marko


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]