Q:

Use Sandy Bridges integrated graphics (or activate switchable graphics) in Ubuntu

I have a HP Pavilion dv6 with Sandy Bridges Core-i7, dual-booted Win7 and Ubuntu 11.04. It also has a 1GB ATI Radeon 6490 discrete graphics card.  In windows, the ATI utility works great and can switch between integrated and discrete graphics with no problem.
In Ubuntu, I have the proprietary ATI driver installed, but when I try to get to the Catlyst Control Center I get this error: 
No ATI graphics driver is installed, or the ATI driver is not functioning properly.
Please install the ATI driver appropriate for you ATI hardware, or configure using aticonfig.

I've looked at the aticonfig options, but can't really make sense of them, and there's only one ATI driver that I can find, so I don't know how I could have installed the wrong one.
In any case, I have given up on being able to use switchable graphics in Ubuntu (unless someone here knows a simple way to make it work), so I would like to set it up to only use the integrated graphics - I pretty much only use Linux for coding, so the discrete graphics are overkill and make my computer run hot and battery die quickly.  Any help is greatly appreciated, I am fairly new to Linux in general.

A:

I finally got it!  I'll put my solution here in hopes that others with Sandy Bridges HP Pavilions can solve their problems as well.
It was as simple as editing the Grub boot options, and replacing quiet splash with modeset=1 xforcevesa
Then in a terminal window, type
sudo -i
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

now when you view the contents of vgaswitcheroo/switch (you may have to sudo to view them) you'll see something like:
0:DIS: :Off:0000:01:00.0
1:IGD:+:Pwr:0000:00:02.0

The first line is my ATI Discreet card, which is now off, and the second is the integrated.  When switching off the ATI card, my battery jumped from 2:10 remaining on a full charge tot 4:00, so it really is worth doing if you're not doing heavy graphics in Ubuntu.  As an added bonus, the Unity interface works now (it's a tiny bit sluggish with only the integrated graphics chipset, but barely noticeable).  To make the change permanent, just add a script to do this on startup.  A few blogs mentioned that due to a bug, you need to power back on the discrete graphics card with a shutdown script to avoid some kind of fan problem on reboot.
Note: If /sys/kernel/debug/vgaswitcheroo doesn't exist, you have to uninstall the ATI proprietary driver and restart the computer
As a final note, this looks like a useful way to give yourself a graphics switching utility, but since my ATI card is really not working at all with Ubuntu I didn't even bother trying it.  http://linuxenvy.blogspot.com/2011/01/tackling-switchable-graphics.html

