IBM Thinkpad G40 & Debian Linux

Xorg

Current versions of the "intel" driver (2:2.3.2-2+lenny6) work pretty much flawlessly, can rotate screens, shut the lid (which hasn't been possible for some time). Config looks like:

Section "Device"
      Identifier      "Internal Video"
      Driver          "intel"
      BusID           "PCI:0:2:0"
      Screen          0
EndSection

Section "Monitor"
      Identifier      "Laptop LCD"
      Option          "DPMS"
      DisplaySize     270 203
EndSection

Section "Monitor"
      Identifier      "Sun GDM-20E20"
      Option          "DPMS"
      HorizSync       30-85
      VertRefresh     48-160
      DisplaySize     337 270
EndSection

Section "Screen"
      Identifier      "Default Screen"
      Device          "Internal Video"
      Monitor         "Laptop LCD"
      Option          "monitor-VGA" "Sun GDM-20E20"
      DefaultDepth    24
      SubSection "Display"
              Depth 16
              Virtual 2304 1024
      EndSubSection
      SubSection "Display"
              Depth 24
              Virtual 1280 1024
      EndSubSection
EndSection

DRI

This seems to just-work™ & glxgears gives me ~400fps, which isn't great but I'm not that fussed. Select the following Character Devices in your kernel setup:-

• Direct Rendering Manager
• Intel 830M, 845G, 852GM, 855GM, 865G
• i915 driver

If you compiled them as a module, insert "i915" into /etc/modules to get it to load on bootup.

Framebuffer

The intelfb fb driver will coexist with the intel X11 driver, however it gets confused when X11 takes over and disables accelleration.

To use intelfb, enable "Intel 830M/845G/852GM/855GM/865G/915G/945G support" under Graphics support in your kernel (compiled in, not a module). Add the following to your kernel command line:

vga=0x318 video=intelfb

Sleep States

The laptop supports S3 (suspend-to-ram) reasonably well. Add the following to your kernel command line:

acpi_sleep=s3_bios

This tells ACPI to run the video BIOS after a resume. It will work fine without, but you need to switch VT's and back again before you can see your mouse cursor.

DSDT Hacks: Extra keys

The DSDT I have modified to include ACPI hotkey support for more keys. This is a similar process for any thinkpad.

1. Install the iasl compiler, copy /proc/acpi/dsdt and decompile it.
2. Look at the source code. Search for "_Q"
3. You should see a whole load of Method (_Q03, 0, NotSerialized). Each one of these is triggered when the Embedded controller receives an event. Through trial and error, I found these events were triggered by some keys:

Adding a call to MHKQ in each of these blocks means that thinkpad_acpi will get told about them. My patch is here.

Recompile the DSDT using iasl -tc into a hex file, and configure the kernel to compile this into it's source code. You could also use the initrd patch, but the new initramfs stuff is a bit cumbersome if that's the only thing you use it for.

CPUFreq

Even if it's predominantly a desktop, this is a good-thing™ to keep heat (and therefore noise) down. I wanted to just use one of the kernel governors and not play around that much. Compile in support for "Intel Pentium 4 clock modulation", and whatever governors you want. Although you can't select ondemand or conservative for the default govenor, you can install sysfs-tools and add to /etc/sysfs.conf:

devices/system/cpu/cpu0/cpufreq/scaling_governor = ondemand