# PowerNow! problem

## amigafan

Hello,

I want to enable PowerNow! on my pavilion notebook and found a deamon called powernowd in portage.

```

bash-2.05b# /etc/init.d/powernowd start

 * Starting powernowd...

powernowd: Couldn't open file /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq

/sbin/runscript.sh: line 529: 10982 Speicherzugriffsfehler  /usr/sbin/powernowd -q ${POWERNOWD_OPTS}

```

And in fact there is no cpufreq/cpuinfo_max_freq in /sys/devices/system/cpu/cpu0/ . cpufreq is compiled into my kernel (2.6.4-gentoo) and the powernow-k7 module is loading during boot.

"Speicherzugriffsfehler" means something like "memory allocation error".

Thanks,

 Kai

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## brodo

 *amigafan wrote:*   

> I want to enable PowerNow! on my pavilion notebook and found a deamon called powernowd in portage.

 

You need kernel support. Assert that 

```
 Power management options (ACPI, APM)  ---> 
```

```
 CPU Frequency scaling  --->     
```

```
<M> AMD Mobile K6-2/K6-3 PowerNow!

<M> AMD Mobile Athlon/Duron PowerNow!

<M> AMD Opteron/Athlon64 PowerNow!

```

are at least set to <M>. Use 2.6.6-rc2-bk1 or later kernel for best results. Then take a look if there's content in /sys/devices/system/cpu/cpu0/cpufreq/ 

If not, take a look at 

```
dmesg | grep powernow
```

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## amigafan

Yes, I had this already but my bios seems to be buggy, because it doesn't find valid pst-tables. The result is that /sys/devices/system/cpu/cpufreq isn't created.

Found a patch for powernow-k7.ko and now its working.

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## brodo

 *amigafan wrote:*   

> Yes, I had this already but my bios seems to be buggy, because it doesn't find valid pst-tables. The result is that /sys/devices/system/cpu/cpufreq isn't created.
> 
> Found a patch for powernow-k7.ko and now its working.

 

If I may ask: what patch?

----------

## amigafan

I'm sorry:

http://consultmatt.co.uk/nx9005/powernow.php

This one works fine for my pavilion ze4511ea, too.

 *brodo wrote:*   

>  *amigafan wrote:*   Yes, I had this already but my bios seems to be buggy, because it doesn't find valid pst-tables. The result is that /sys/devices/system/cpu/cpufreq isn't created.
> 
> Found a patch for powernow-k7.ko and now its working. 
> 
> If I may ask: what patch?

 

----------

## brodo

 *amigafan wrote:*   

> I'm sorry:
> 
> http://consultmatt.co.uk/nx9005/powernow.php
> 
> This one works fine for my pavilion ze4511ea, too.
> ...

 

But it is quite risky -- I wouldn't do it. Better try out whether the ACPI perflib support in 2.6.6-rc2-bk1 works.

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## amigafan

Why do you think its risky? Can you give some more information?

 *brodo wrote:*   

>  *amigafan wrote:*   I'm sorry:
> 
> http://consultmatt.co.uk/nx9005/powernow.php
> 
> This one works fine for my pavilion ze4511ea, too.
> ...

 

----------

## brodo

 *amigafan wrote:*   

> Why do you think its risky? Can you give some more information?
> 
>  *brodo wrote:*    *amigafan wrote:*   I'm sorry:
> 
> http://consultmatt.co.uk/nx9005/powernow.php
> ...

 

You assume the same frequency/voltage steps which are valid for a different CPU to work also on your system. However, the steps might be different, and you might either run it at an undefined frequency OR with a too low voltage (=>unstable) OR with a too high voltage => can burn through, I fear. I haven't heard such a report yet; but I wouldn't bet money it doesn't happen.

----------

