Re: intel_pstate: Haswell i7-4600M refuses to enter lower Package States

From: Andy Lutomirski
Date: Tue Feb 25 2014 - 21:49:13 EST


On 02/20/2014 04:29 AM, Dieter Mummenschanz wrote:
> Hello,
>
> on my Lenovo T440p Laptop the Haswell i7-4600M CPU refuses to enter lower PC states resulting in 14-15 Watts continuous power drain even if the system is idle and every tunalbes in powertop 2.5 are enabled. The issue is reproducable with Kernel versions 3.13 up to 3.14-rc3.
>
> Did anyone else experience a similar issue?

Something's confused here. Do you mean P-states (i.e. performance
states or "frequency" settings) or PC-states (i.e. "package C-states")?
I suspect that you mean the latter, in which case intel_pstate has
nothing to do with the problem.

The relevant diagnostic is the output from turbostat.

--Andy
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