[ltp] CPU running ??? but why????

Florian Reitmeir linux-thinkpad@linux-thinkpad.org
Sun, 8 Jun 2008 11:42:41 +0200

On Sat, 07 Jun 2008, Peter F. Patel-Schneider wrote:

> As far as I know, this is an unexplained phenomenon that has been around
> for at least a year now.  My Lenovo T60p exhibits this behaviour
> sometimes, but not all the time.  Even more strangely, the aberrant
> behaviour comes and goes - for a few days it happens quite reqularly,
> then there is no problem for weeks on end.
> Several people, myself included, have asked in various fora about the
> problem, including the powertop mailing list, accessible at
>   http://www.bughost.org/mailman/listinfo/power
> see 
>   http://www.bughost.org/pipermail/power/2007-May/000337.html 
> for the first report that I can find.  I just noticed a recent report on
> the problem
>   http://www.bughost.org/pipermail/power/2008-June/001371.html
> So what is causing the problem?  The guessing, and as far as I know it
> is only guessing, is that some DMA activity is causing the wakeups, but
> I don't even know enough about the situation to figure out whether
> explanation makes any sense.  Even if this is the case, I haven't seen
> any hints on how to attempt to fix the problem, or even which of the
> many devices built in to my T60p is the source.  I don't even know how
> widespread the problem is.
> All in all, quite frustrating.

just run powetop in one terminal
and run an other terminal in which you remove kernel modules, one by one.

typical these kernel modules first:
	- usb
	- firewire
	- sound hardware
	- yenta socket

take your time, if its a hardware problem you should be able to debug it, in
about 30 mins.

Florian Reitmeir