I have a sony VPCZ12 laptop. It has those dual video cards that are a pain to get working in linux. The new 2.6.35 kernel is supposed to support that with the vga_switcheroo module which is supposed to be located in /sys/kernel/debug on >2.6.35.The problem is that when I boot my laptop, it freezes at a blackscreen unless I boot with options i915.nomodeset=0. It won't boot into X, but I can get to a terminal which is fine. But then vga_switcheroo isn't in /sys/kernel/debug.Is this a ubuntu bug on how the kernel is compiled? Or is it because I have to boot with i915.nomodeset?The livecd boots into X just fine, but I've never found a way to get X working on the installation. There's a lot of information about linux on the z12 but most of it is either outdated, doesn't work, or just plain doesn't make any sense
vga_switcheroo not in /sys/kernel/debug in 2.6.35-22 (kubuntu maverick)
kernel;kernel modules
You need to have a kernel with vga_switcheroo enabled and KMS, i.e. kernel mode setting, active (which you haven't as you boot with nomodeset).To check if vga_switcheroo is enabled in the kernel, have a look into the Ubuntu config of your kernel. You should find it in /boot with a name along the lines of /boot/config-2.6.35-XX-generic with XX some number corresponding to your kernel.If it is not enabled, you find a custom Ubuntu kernel with vga_switcheroo enabled at http://www.ramoonus.nl/2010/08/linux-kernel-2-6-35-installation-guide-for-ubuntu-linux/ 