Just passing along what I've experienced with this bug. I also posted this on the duplicate bug (#834037) in case one of them is marked as a duplicate.
X220 i7-2620M I experience the difference in power usage w/ 3.x kernels and setting the i915.i915_enable_rc6=1 parameter fixes this issue while bringing back the video corruption. The video corruption for me takes the form of light and dark grey horizontal stripes covering the screen. It always kicks in running on battery, when the screen is waking up from X having it off (due to lid being closed or DPMS turning it off). If I close and reopen the lid again I can see the correct display for a second before the stripes cover it up again. The system is interactive and I can blindly work with the windows. I've found that plugging in my external monitor and using xrandr to enable it fixes the problem. I've been messing around with various xrandr commands to see if I can come up with something that fixes the problem without having the actual physical external monitor plugged in but have had no luck so far. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/818830 Title: [Sandy Bridge] serious power regression from kernel 3.0.0-6 to 3.0.0-7 (rc6 disabled) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/818830/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs