[Tfug] no cpu scaling lately on a core2 duo

Tom Rini trini at kernel.crashing.org
Fri Jan 27 15:49:48 MST 2012


On Fri, Jan 27, 2012 at 3:40 PM, Tom Rini <trini at kernel.crashing.org> wrote:
> On Fri, Jan 27, 2012 at 3:33 PM, JD Rogers <rogersjd at gmail.com> wrote:
>>>
>>> First things first.  If you change to 'performance' do you go up to 2GHz?
>>
>> Good question. No, it stays at 1GHz. And the plot thickens, because  I
>> just noticed /sys/devices/system/cpu/cpu*/cpufreq/bios_limit says
>> 1GHz, but I know the bios is set to allow scaling. And again, I point
>> to the fact that the speed does spike momentarily when I plug/unplug
>> the AC.
>
> So, there's your culprit.  The BIOS fills out part of the table
> incorrectly, Linux obeys and Windows doesn't.  I haven't looked hard
> enough to see if there's a workaround because for me I can live with
> always max frequency (so I disabled speedstep in the BIOS).

This finally got me to hit up google and I found
http://woolie.co.uk/technology/dell-laptop-stuck-at-800mhz-ubuntu-fix
which says it's a simple command line option to pass to get this
ignored.  I'll give it a spin on my box when I restart it next.

-- 
Tom




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