High cpu temperature and fan when loading i195 kernel module

[Francois Tigeot]

Hi,

On Sat, May 06, 2017 at 12:14:54PM +0200, Luca Franchini wrote:
> 
> I'm trying dragonfly on my new Thinkpad T460p (Intel HD 530 + Nvidia GPU).
> 
> Loading i195 kernel module seems to produce high cpu stress.
> 
> Before:
> 
> hw.sensors.cpu0.temp0: 37.00 degC (node0 core0 temp), OK
> 
> Right after i915 is loaded:
> 
> hw.sensors.cpu0.temp0: 60.00 degC (node0 core0 temp), OK

There seems to be something very wrong with Skylake power management on
laptops.
My Thinkpad x260 doesn't go as high temperature-wise but suffers from
recurrent micro-freezes which sometimes render it unusable.

Linux users reported similar issues last year when Skylake laptops began
to become common. This is probably the most famous blog entry about skylake
power management issues:
https://mjg59.dreamwidth.org/41713.html

Linux has seen plenty of Skylake related commits since then so the issue
appears to be fixed in recent kernels.
Someone would probably need to bisect the Linux git tree in order to find
out what exactly did the trick.

All I can say so far is this particular commit seems a good contender for
my skylake overheat/hang problems:
https://patchwork.kernel.org/patch/9042341/

I tried to load the new proprietary firmware but that didn't fix anything.

-- 
Francois Tigeot