Comment 0 for bug 995005

On my Samsung NC20 Netbook the BIOS hides the C3 C-state when the AC power is connected, but it should show up and work as soon as the AC power is disconnected.

This expected behavior worked fine as long as I used Oneiric. But now I upgraded to Precise and now C3 does not work anymore after disconnecting the AC power.

I have verified, that booting the Oneiric kernel 3.0.0-19.33 instead of the Precise Kernel 3.2.0-24.37 (same userspace) fixes the problem.

To gather some information, I executed this command with the Precise kernel
  grep -r "" /sys/devices/system/cpu/cpu0/cpuidle/
in different system states:
1. newly booted without having the AC power attached
2. having the AC power attached (without C3, as expected)
3. now after having the AC power disconnected (not functional C3 --> bug)

The output is combined in the attached file "cpuidle.txt".