xrandr doesn't do what I expect. Instead I get BadMatch

searchingfortao · 07-22-2010, 12:47 PM

I'm just getting the hang of xrandr, so it's likely that I've missed something, but I have no idea what it is.

Here's my setup: Two monitors, one Thinkpad x41 laptop running at 1024x768, and another monitor running 1440x900 to the right of the laptop. Based on everything I've found online, one of the following should do let me spread a single desktop across the two monitors:

Code:

xrandr --output VGA1 --mode 1440x900 --pos 1024x0 --right-of LVDS1
xrandr --output VGA1 --mode 1440x900              --right-of LVDS1
xrandr --output VGA1 --auto          --pos 1024x0 --right-of LVDS1
xrandr --output VGA1 --auto                       --right-of LVDS1
xrandr --output VGA1 --mode 1440x900 --pos 1024x0 --right-of LVDS1 --mode 1024x768
xrandr --output VGA1 --auto          --pos 1024x0 --right-of LVDS1 --mode 1024x768
xrandr --output VGA1 --auto                       --right-of LVDS1 --mode 1024x768

...but none of them do. All of them instead give me a full 1024x768 on the laptop, but only give me the first 200 pixels on the left of the larger monitor. The rest of the screen in inaccessible.

Any ideas?

adamk75 · 07-22-2010, 07:20 PM

Try:

Code:

xrandr --output VGA1 1440x900 --right-of LVDS1 --output LVDS1 --mode 1024x768

In all the examples you tried, you're only specifying one --output. In the last three examples, you're using the argument to --right-of (LVDS1) as if it was an argument to --output, but you are missing the --output.

searchingfortao · 07-23-2010, 12:21 PM

Quote:

xrandr --output VGA1 1440x900 --right-of LVDS1 --output LVDS1 --mode 1024x768

That just resulted in getting a blob of help text, so I added a --mode argument:

Quote:

xrandr --output VGA1 --mode 1440x900 --right-of LVDS1 --output LVDS1 --mode 1024x768

Still no joy though. I think I've resigned myself to just using one monitor on this laptop as it doesn't appear to like xrandr at all :-( For instance, to get the monitor to work at full resolution, I had to specify "--left-of" to get it to work. S'alright. Thanks for your help :-)

adamk75 · 07-23-2010, 12:50 PM

Yeah, sorry about the missing --mode. This is very odd. What video card and drivers are you using?

Adam