Hello,
I'm observing a high CPU usage at my ThinkPad T420 (i5-2540M CPU), w/ integrated intel graphic.
Powertop-2.1 shows that the GPU is always at 100%, although I've defined these settings : $> cat /etc/modprobe.d/i915.conf options i915 i915_enable_rc6=7 lvds_downclock=0
Kernel 3.5.4 works fine, I don't see any differences in dmesg output.