patch: p4tcc and speedstep cpufreq drivers

[Nate Lawson]

Kevin Oberman wrote:
>>Date: Wed, 02 Mar 2005 15:28:52 -0800
>>From: Nate Lawson <nate at root.org>
>>If you look elsewhere, the design is stated more clearly and shows the 
>>reading that enabling On-Demand disables Automatic mode is incorrect.
>>
>>Intel Software Developer's Manual, Volume 3, 13.15.3:
>>"If on-demand clock modulation and TM1 are both enabled and the thermal 
>>status of the processor is hot ..., clock modulation at the duty cycle 
>>specified by TM1 takes precedence, regardless of the setting of the 
>>on-demand clock modulation duty cycle."
>>
>>Empirical testing shows TM1 kicks in around 75C and THERMTRIP is 
>>somewhere near 100C.  The separate THERMTRIP feature disables the 
>>processor completely if TM1 or 2 fail to stop the temperature from rising.
>>
>>http://www.digit-life.com/articles2/p4-throttling/
> 
> 
> OK. This makes me feel a bit better, but I still think I'll leave TCC
> out of the equation as it makes the various frequency steps vary uneven
> to the point that lowering dev.cpu.0.freq would increase performance
> (and the reverse, as well) and it causes my system to hang when
> throttled back too far. It never hangs with TCC disabled although my
> lowest "frequency" is now just 150 MHz.
> 
> By the way, I am still delighted in the cpufreq addition to the system.
> It gives me excellent control of CPU speed to stretch my battery life.
> All I really need is a desktop tool (maybe a gnome applet) to let me
> adjust freq easily. I may just try to write that myself if I get some
> time before someone else gets to it.

I'll try to see if I can find a way to notice bad states and disable 
them automatically.  Perhaps your CPU has some errata.

Regarding the gnome applet, too late, marcus@ has done that.  :)

-- 
Nate