Brightness controls not adjusting the brightness in ubuntu 10.10 64 bit on hp dm3t notebook

Question

I picked up an hp dm3t laptop with intel HD graphics and installed ubuntu 10.10 64 bit on it. It works great -- the only problem is that the brightness controls on the keyboard don't work. The brightness is always at full. When I try to adjust it down, the indicator graphic indicates that it's going down but the actual brightness doesn't change. Is there anything that I can try to make this work? I'd really appreciate any help.

Answer 1

1. Run this command:

   sudo gedit /etc/default/grub
   

2. Change the line:

   GRUB_CMDLINE_LINUX=""
   

   into

   GRUB_CMDLINE_LINUX="acpi_osi=Linux"
   

3. Then run:

   sudo update-grub
   

4. Restart Linux.