Lenovo T41p

From openSUSE

How to Configure Dualhead for T41p

If you want to run a dualhead configuration with a T41p, at least with openSUSE 10.2 this can be a challenging task. After some tweaking, I can say it is possible with some limitations.

Used System

• T41p with FireGL Mobility T2
• Port Replicator
• external Monitor: LG W2284F
• openSUSE 10.2

The Laptop LCD has a resolution of 1400x1050@60Hz, the LG has a resolution of 1680x1050@60Hz. Combined, they should just offer a very broad screen with a resolution of 3080x1050@60Hz.

Creating a Template Configuration with SAX2

I did not find a method to completely configure this system with sax2 in a way that both monitors are in the correct mode. The default that I got was 1280x1024 for both monitors, means 2560x1024 which is not exactly what I wanted to have. When running yast2 with the external monitor attached at the analog VGA socket of the port replicator, sax2 comes up with the LG monitor as main monitor. However, the primary monitor is always the LCD of the Laptop. To change this, run Change Configuration and then change the internal monitor to a LCD with 1400x1050@60Hz.

Next, activate the Dualhead configuration and select the external monitor. This would probably work with any monitor that has a resolution with less or equal than 1400x1050. If your monitor is bigger, just select a LCD with 1400x1050@60Hz. By doing this, I got a working configuration with 2800x1050 which is already way better than the default provided by sax2. There are several more steps necessary to get the right resolution on the external monitor. All of the changes have to be done to the main configuration file /etc/X11/xorg.conf.

1. Create a modeline for your desired external resolution. To do this, run the program cvt with the right parameters. For example, the modeline for a 1680x1050@60Hz monitor can be created with the command cvt 1680 1050 60. Add the generated modeline to the "Modes" section.

1. The "radeon" driver seems to ignore any resolutions that are not available in the "Modes" line of the "Screen" section. Therefore, go to the "Screen" section, and search for the "Display" subsection that holds the "Modes" of your default colour depth. Commonly, this is the subsection with the entry "Depth 24". At the end of the "Modes" in this section, add the extra resolution "1680x1050".

1. Now, it is just one small step left to do: Go to the "Device" section and search for the line containing "MetaModes". The first entry in there should look like "1400x1050,1400x1050;...". If your external Monitor is to the right of your laptop, change it to look like "1400x1050,1680x1050;...". If the external Monitor is on the left, just change the other value.

If I did not miss anything, your system should come up with an extra broad screen next time when X is started.

How to Configure a T41p to use only the External Monitor

Using the dualhead configuration has one serious drawback. At least the T41p that I had to configure could not use the DVI connector when using the internal LCD screen. This resulted in a reduced picture quality that I did not want to have.

NOTE: I needed some time to find the reason why the external DVI was not available to me. To activate this connector, go to the BIOS of the T41p (with the F1 key at startup) and change the video settings to support the external DVI (or DVI and VGA e.g.). However, after doing this, I did not get a picture on the internal LCD screen anymore. First, add the modeline and resolution string like described above.

The main difference to the Dualhead configuration for me was:

1. add Option "MonitorLayout" "TMDS, LVDS" to the "Device" section.

1. remove Option "MergedFB" from the configuration (or comment it with #).

1. add Option "SWcursor" "on" to the "Device" section.

If the X-Server is able to read the monitor data with DDS, this should be ok to run the external monitor only. For more information about the "radeon" driver, have a look at the manual page man 4 radeon.