Re: cpufreq stops working after a while

[Andrew Morton <akpm@osdl.org>]

On Fri, 11 Aug 2006 14:25:26 -0400
Mark Lord <lkml@rtr.ca> wrote:

> One of my notebooks (Dell Latitude X1) has a 1.1GHz Pentium-M ULV processor.
> This chip can change CPU speeds from 600 -> 800 -> 1100 Mhz.
> 
> I use speedstep-centrino with it, and after boot all is usually okay.
> But after a few hours of operation, it stops shifting to the highest frequency
> even under continuous 100% load (or not).  Eventually it gets stuck at 600Mhz
> and stays there until I reboot.
> 
> Sometimes rebooting doesn't even restore it.
> 
> /sys/devices/system/cpu/cpu0/cpufreq is all very normal looking,
> showing the available frequencies and other info.  All of the attribs
> there look fine, except for "scaling_max_freq", which is what seems
> to gradually get set smaller.  For instance, right now it is set to 800000,
> and it won't let me change it (echo 11000000 > scaling_max_freq has no effect.
> 
> WHY?

cpufreq seems to have relatively frequent problems.

>  And how can I fix it?

You could start by telling us which kernel versions are affected ;)