Re: Regression in 4.8 - CPU speed set very low
From: Rafael J. Wysocki
Date: Thu Sep 29 2016 - 16:45:45 EST
On Thursday, September 29, 2016 08:56:16 AM Srinivas Pandruvada wrote:
> On Thu, 2016-09-29 at 14:19 +0200, Rafael J. Wysocki wrote:
> > > My laptop was inadvertently put to sleep while I was gone. I forgot
> > > to leave a
> > > note for my wife and she quieted the noisy cpu fan. :)
> > It looks like in 4.8-rc we made a change that caused the "high" trip
> > point to
> > be acted on.
> This high trip point we don't expose in thermal subsystem (the thermal
> zone dump didn't show this anywhere as a trip). This is exposed by
> core-dts driver only. This is the point BIOS is supposed to act, I
> guess that's why you are seeing 50% clock modulation.
Right. That's SMM kicking in.
The real problem is that we get stuck at 400 MHz.