Re: Cpufreq on kernel 2.6.18

[Joan Moreau <joan.moreau@m4x.org>]

Luca,

I have exactly the same problem on my pentium M 2Ghz.

Only "cpufreq_centrino"  works under linux 2.6.18 (i..e /sys has 
relevant info) but cpufredq does not work anymore (frequancy not changeable)

Has anybody found any fixes ?

Thanks

Joan

Luca wrote:
> On Fri, 6 Oct 2006 16:08:22 -0700
> "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> wrote:
>
>   
>>  
>>
>>     
>>> -----Original Message-----
>>> From: cpufreq-bounces@lists.linux.org.uk 
>>> [mailto:cpufreq-bounces@lists.linux.org.uk] On Behalf Of Luca
>>> Sent: Friday, October 06, 2006 1:01 PM
>>> To: cpufreq@lists.linux.org.uk
>>> Subject: Cpufreq on kernel 2.6.18
>>>
>>> Hello,
>>> I just updated the kernel from 2.6.15.2 to 2.6.18 and the 
>>> frequency scaling of my Centrinlo Laptop stopped working 
>>> (keeping the same configuration).
>>> The dir /sys/devices/system/cpu/cpu0/ is empty and I don't 
>>> know which other tests I could make.
>>> I also tried to move CONFIG_X86_ACPI_CPUFREQ from builtin to 
>>> module: loading the module does not give any information nor any error.
>>> I need 2.6.18 for other drivers, so it would be really nice if 
>>> I could solve this problem that seems to be the only driver 
>>> that's not working properly (and my battery would be much happier :) )
>>> If you need more informations just tell me.
>>>
>>>       
>> Can you enable CPU_FREQ_DEBUG in your config and pass "cpufreq.debug=3"
>> in kernel parameter and send in the dmesg log.
>>     
>
> I found something, and maybe I have to ask excuse, because now it's working..
> Anyway something has changed and that's the reason that fooled me: on my old logs, with the old kernel I had:
>  acpi-cpufreq: CPU0 - ACPI performance management activated.
> So I focused my attention on the module acpi-cpufreq. Inserting it, even with debug activated (cpufreq.debug=3 forgot to pass it at boot, but now seems not so important...) doesn't tell anything at all (and doesn't work).
> I was playing with other modules, and I found that loading the module speedstep-centrino enables cpufreq (even if on kernel log doesn't print anything).
> So something has changed in the software support for my hardware. I'm sorry for not having understood earlyer. Since I'm writing here, can I kindly ask you a short explanation on this difference between two different kernels, on the same hardware.
>
> Thanks for the fast answer,
> 				Luca.
>
>
> PS: thanks for the work on cpufreq: with the moderm pcs with cpu pull to the limit I think it's really useful to be able to force lower frequency, when you don't need all the computeing power.
>
>   
>> Thanks,
>> Venki
>>     
>
>
>