L-P Huberdeau's blog

A few months ago, I made an update on my system running 7.10 and it turned bad. The package actually got corrected very fast, but I had no time to waste so I re-installed my system. I had been upgrading my Kubuntu distribution since 6.06 and didn’t have any CD for 7.10. To get multiple screens working and the non-conventional screen resolution of my laptop, I had been carrying a heavily customized version of my xorg.conf file and a few scripts to handle the different resolutions I could need (dual head at home, single head when on the road, and a cloned 1024×768 for those times I had to present. Upgrading is always a mess, but I didn’t feel like downloading all updates, so I got an alpha release for 8.04. I was surprised to see it first correctly configured my resolution to 1280×800 and didn’t need that 915resolution fix.

OK. Maybe that wasn’t the smartest move. To keep the story short, I couldn’t get the extra monitor on my desk ever since that upgrade. My xorg.conf file would not work anymore and the configuration tools were broken. Since I had too much to do, I couldn’t get the time to investigate, but today I did. I seems like the way X is handled is having a huge face lift. There was something comforting about the xorg.conf file. If something messed up, you could always fix it by knowing some arcane lines and searching for solutions from lynx. However, it seems like that file is about to go extinct. This is what my file looks like at this time:

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "kbd"
        Option          "XkbRules"      "xorg"
        Option          "XkbModel"      "pc105"
        Option          "XkbLayout"     "ca"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
EndSection

Section "Device"
        Identifier      "Configured Video Device"
EndSection

Section "Monitor"
        Identifier      "Configured Monitor"
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Monitor         "Configured Monitor"
        SubSection "Display"
                Depth 24
                Virtual 2560 1024
        EndSubSection
EndSection

It really is different from the 222 lines file I used to carry over from installation to installation. The only thing specific to my system on it is this section:

        SubSection "Display"
                Depth 24
                Virtual 2560 1024
        EndSubSection

The only purpose of it is to tell the Intel driver to allocate a larger framebuffer at X load time in case I want to extend the Desktop. It made sense before to allocate only what was needed at load, but since you can now change the resolution dynamically, reloading X is not an option.

With fairly simple commands, the resolution can now be changed and it’s mostly safe. Never prevented me from using my computer. The only problem is that the GUIs are lacking at this time, so those commands may not be good for everyone and there are some parameters I wish I didn’t have to understand.

To get my second monitor working, I had to use these commands:

xrandr --output VGA --right-of LVDS
xrandr --newmode 1280x1024 108.88 1280 1360 1496 1712 1024 1025 1028 1060 -HSync +Vsync
xrandr --addmode VGA 1280x1024
xrandr --output VGA --mode 1280x1024

Other than the second line, this is fairly simple. Tell it where the second monitor should go, register a resolution (Google told me the line, I didn’t figure it out), tell that the resolution applies to the VGA monitor and activate it. In the blink of an eye, the desktop is extended. No need to restart X anymore.

All this messing around with resolutions was always annoying for laptops running Linux. On desktop, all you have to care about is your own setup. However, with a laptop, the setup can really be anything. Now if I could just have a GUI to select the monitor resolution, I would be fully happy. I guess this is all going to arrive before the final release of 8.04. Still, the situation is a lot better than it used to be.

xrandr could use better documentation, but I doubt it was meant to be used by end users. Just calling the command lists the available screens and the known resolutions for them, so that is easy enough. However, the –help option does not help so much with what is expected as an argument. There is some help available on forums and such if you know what to search for.