Cpufreq on kernel 2.6.18

Cpufreq on kernel 2.6.18

[Luca]

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.

Bests,
	Luca.


my cpu is:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.73GHz
stepping        : 8
cpu MHz         : 1729.621
cache size      : 2048 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx est tm2
bogomips        : 3462.49


-- 
       .-------------------------------------.
  -=<(§  Luca <morpheus AT ferrara.linux.it>  §)>=-
       °-------------------------------------°

RE: Cpufreq on kernel 2.6.18

[Pallipadi, Venkatesh]

 

>-----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.

Thanks,
Venki

Re: Cpufreq on kernel 2.6.18

[Luca]

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


-- 
       .-------------------------------------.
  -=<(§  Luca <morpheus AT ferrara.linux.it>  §)>=-
       °-------------------------------------°

Re: Cpufreq on kernel 2.6.18

[Joan Moreau]

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
>>     
>
>
>   

Re: Cpufreq on kernel 2.6.18

[Luca Barion]

I can tell you that on my centrino with the module cpufreq_centrino 
cpufreq works (at least I was able to set powersave governor, the orther I 
didn't try yet).
You could try to build any feature regarding cpufreq as module, and 
loading and unloading each: I found that some modules conflict with other 
preventing from working correctly (also on a desktop p4 dualcore).
 	Luca.

On Sun, 8 Oct 2006, Joan Moreau wrote:

> 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
>>> 
>> 
>> 
>>

Re: Cpufreq on kernel 2.6.18

[Joan Moreau]

yes, the governor process works, but the frequency stays unchanged , 
whatever is the governor :-(

Is anybody having the same problem ?

Thanks

Joan

Luca Barion wrote:
> I can tell you that on my centrino with the module cpufreq_centrino 
> cpufreq works (at least I was able to set powersave governor, the 
> orther I didn't try yet).
> You could try to build any feature regarding cpufreq as module, and 
> loading and unloading each: I found that some modules conflict with 
> other preventing from working correctly (also on a desktop p4 dualcore).
>     Luca.
>
> On Sun, 8 Oct 2006, Joan Moreau wrote:
>
>> 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
>>>>
>>>
>>>
>>>
>

RE: Cpufreq on kernel 2.6.18

[Pallipadi, Venkatesh]

 

>-----Original Message-----
>From: Joan Moreau [mailto:joan.moreau@m4x.org] 
>Sent: Sunday, October 08, 2006 1:25 PM
>To: Luca
>Cc: Pallipadi, Venkatesh; cpufreq@lists.linux.org.uk
>Subject: Re: Cpufreq on kernel 2.6.18
>
>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

The change from acpi-cpufreq to speedstep-centrino driver from 2.6.16 to
2.6.18 is intentional. Looks like your platform can support both these
drivers and Linux is picking the best driver, that is speedstep centrino
in this case. So, everything is fine until that point.

But, I don't know why cpufreqd does not work with speedstep-centrino. As
long as these /sysfs interfaces are there, cpufreqd should work. Is it
not inserting the speedstep-module and hence it is failing? Can you try
manually switching to performance and powersave governors and make sure
frequency is changing. Something like this after you have
speedstep_centrino working.

#cd /sys/devices/system/cpu/cpu0/cpufreq
// I am assuming that this is a Centrino CPU with single logical CPU.
#cat  scaling_available_frequencies
#echo performance > scaling_governor
#cat cpuinfo_cur_freq
#echo powersave > scaling_governor
#cat cpuinfo_cur_freq

Now if this works, you can go ahead and try ondemand governor and see
whether that is working
#echo ondemand > scaling governor
// Leave system idle for couple of seconds
#echo cpuinfo_cur_freq
// Run some infinite loop code or some other load to keep CPU busy
#echo cpuinfo_cur_freq

Now if this also works, then there is something wrong with cpufreqd..
If any of these doesn't work, then there is some problem in kernel.

Thanks,
Venki

RE: Cpufreq on kernel 2.6.18

[Pallipadi, Venkatesh]

 

>-----Original Message-----
>From: Luca [mailto:morpheus@ferrara.linux.it] 
>Sent: Sunday, October 08, 2006 10:37 AM
>To: Pallipadi, Venkatesh
>Cc: cpufreq@lists.linux.org.uk
>Subject: Re: Cpufreq on kernel 2.6.18
>
>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.
>

Change from acpi-cpufreq to speedstep-centrino is a long story. You can
find some background here
http://bugme.osdl.org/show_bug.cgi?id=6005


Thanks,
Venki

Re: Cpufreq on kernel 2.6.18

[Luca]

On Mon, 16 Oct 2006 06:34:38 -0700
"Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> wrote:

...
> 
> Change from acpi-cpufreq to speedstep-centrino is a long story. You can
> find some background here
> http://bugme.osdl.org/show_bug.cgi?id=6005
> 
> 
> Thanks,
> Venki

Thanks for the information: at the end I can understand the trick :)

	Luca.

-- 
       .-------------------------------------.
  -=<(§  Luca <morpheus AT ferrara.linux.it>  §)>=-
       °-------------------------------------°

Re: Cpufreq on kernel 2.6.18

[Joan Moreau]

Thanks for the tip.

I guess the error comes from the Kernel, as all interfaces are their, 
but the frequency is not changeable in /sysfs :-(



Pallipadi, Venkatesh wrote:
>  
>
>   
>> -----Original Message-----
>> From: Joan Moreau [mailto:joan.moreau@m4x.org] 
>> Sent: Sunday, October 08, 2006 1:25 PM
>> To: Luca
>> Cc: Pallipadi, Venkatesh; cpufreq@lists.linux.org.uk
>> Subject: Re: Cpufreq on kernel 2.6.18
>>
>> 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
>>     
>
> The change from acpi-cpufreq to speedstep-centrino driver from 2.6.16 to
> 2.6.18 is intentional. Looks like your platform can support both these
> drivers and Linux is picking the best driver, that is speedstep centrino
> in this case. So, everything is fine until that point.
>
> But, I don't know why cpufreqd does not work with speedstep-centrino. As
> long as these /sysfs interfaces are there, cpufreqd should work. Is it
> not inserting the speedstep-module and hence it is failing? Can you try
> manually switching to performance and powersave governors and make sure
> frequency is changing. Something like this after you have
> speedstep_centrino working.
>
> #cd /sys/devices/system/cpu/cpu0/cpufreq
> // I am assuming that this is a Centrino CPU with single logical CPU.
> #cat  scaling_available_frequencies
> #echo performance > scaling_governor
> #cat cpuinfo_cur_freq
> #echo powersave > scaling_governor
> #cat cpuinfo_cur_freq
>
> Now if this works, you can go ahead and try ondemand governor and see
> whether that is working
> #echo ondemand > scaling governor
> // Leave system idle for couple of seconds
> #echo cpuinfo_cur_freq
> // Run some infinite loop code or some other load to keep CPU busy
> #echo cpuinfo_cur_freq
>
> Now if this also works, then there is something wrong with cpufreqd..
> If any of these doesn't work, then there is some problem in kernel.
>
> Thanks,
> Venki
>
>   

RE: Cpufreq on kernel 2.6.18

[Pallipadi, Venkatesh]

 

>-----Original Message-----
>From: Joan Moreau [mailto:joan.moreau@m4x.org] 
>Sent: Monday, October 16, 2006 1:00 PM
>To: Pallipadi, Venkatesh
>Cc: Luca; cpufreq@lists.linux.org.uk
>Subject: Re: Cpufreq on kernel 2.6.18
>
>
>Thanks for the tip.
>
>I guess the error comes from the Kernel, as all interfaces are their, 
>but the frequency is not changeable in /sysfs :-(
>
>

If you manually set the governor to userspace and change the frequency
by writing to cpufreq_setspeed does the frequency change?

This looks like same as
http://bugzilla.kernel.org/show_bug.cgi?id=7376

Can you confirm?

Thanks,
Venki