Comment 17 for bug 348694

It was suggested to me out of band to look at the output of powertop.

So I enabled C States in the BIOS and got Jaunty running again (hitting the power switch 30-some times and the Ctrl key on the keyboard 500-some times to create interrupts to get it to where I could run powertop.

powertop showed the system was in the C3 state some of the time.
It reported interrupts from hpet3, hpet2, uhci_hcd:usb4, uhci_hcd:usb7, and Dell Laser mouse.

But it ONLY would refresh when I did something with the keyboard or mouse to get interrupts. The HPET 3 and HPET 2 interrupts are NOT waking the system out of the C3 state. Once a keyboard or mouse actually DOES wake the system, the enqueued HPET interrupt is handled.

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When I boot the same Jaunty LiveCD and add "hpet=disable" the output of powertop seems quite sensible. It updates correctly. It says that the system is spending nearly all of its time in state C3 with 60% of the interrupts coming from something called, "<interrupt> extra timer interrupt". The next most frequent source of interrupts is "hr timer_start (tick_sched_timer)".

Given this data from powertop, do you folks think we're talking a BIOS bug, a hardware bug, or a Linux bug?