freqency scaling on compaq nx9010

freqency scaling on compaq nx9010

[Thomas Eschenbacher]

Hi,

I have a compaq nx9010 laptop, running on kernel 2.4.9-gentoo-r13, with 
ACPI enabled and speedstep for frequency scaling. Speedstep itself works 
rather fine, but I wonder about the available scaling frequencies:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
gives only "668000 692000" ?

...and this is also what speedstep does - it switches between these two 
frequencies, 96% and 100% speed. Isn't this absolutely nonsense? Only 4% 
speed difference !?

I now have fixed the bios' DSDT and built my own one in the kernel - no 
change. Furthermore I cannot find the numbers 668000, 692000, 668 and 
692, neither in decimal, nor in hex in the decompiled dsdt.

On the other hand my dsdt contains two entries in the _PSS section, one 
for 3059MHz (100%) and one for 1596MHz (~50%) - but those two 
frequencies appear nowhere in /proc or /sys/devices/... !?

what goes wrong here ?

Is speedstep independend from ACPI ?

Thomas



-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

Re: freqency scaling on compaq nx9010

[Dominik Brodowski]

Hi,

Please post the contents of all files in
/sys/devices/system/cpu/cpu0/cpufreq/ 

On Sun, Jan 09, 2005 at 07:47:09PM -0300, Thomas Eschenbacher wrote:
> Hi,
> 
> I have a compaq nx9010 laptop, running on kernel 2.4.9-gentoo-r13, with 
> ACPI enabled and speedstep for frequency scaling.
Which variant of speedstep?

> ...and this is also what speedstep does - it switches between these two 
> frequencies, 96% and 100% speed. Isn't this absolutely nonsense? Only 4% 
> speed difference !?

It most likely is nonsense...

> On the other hand my dsdt contains two entries in the _PSS section, one 
> for 3059MHz (100%) and one for 1596MHz (~50%) - but those two 
> frequencies appear nowhere in /proc or /sys/devices/... !?

What does using the acpi-cpufreq driver lead to?

> Is speedstep independend from ACPI ?

It depends on the driver and sometimes on driver settings whether it is
independend from ACPI or not.

	Dominik


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

Re: freqency scaling on compaq nx9010

[Thomas Eschenbacher]

Dominik Brodowski wrote:
> [...]
>>I have a compaq nx9010 laptop, running on kernel 2.6.9-gentoo-r13, with 
>>ACPI enabled and speedstep for frequency scaling.
> 
> Which variant of speedstep?

The file "scaling_driver" told me it was "speedstep-smi".
(which makes no sense to me, I have an ALI and no Intel chipset...)
No idea what it really was, I saw no kernel message about
speedstep or so.
(ACPI version is 20040816)

> [...]
>>On the other hand my dsdt contains two entries in the _PSS section, one 
>>for 3059MHz (100%) and one for 1596MHz (~50%) - but those two 
>>frequencies appear nowhere in /proc or /sys/devices/... !?
> 
> What does using the acpi-cpufreq driver lead to?

...to success :-)   Great, this was the right hint!

I kicked out all speedstep stuff from my kernel config and now I see 
30590000 and 15960000 in 
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies -
the same values as in my DSDT, using acpi-cpufreq as driver.

So what would be the advantage of speedstep over acpi-cpufreq ?
Does it also switch core voltage or do other things?

thanks for the quick reply and the help,
    Thomas


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

Re: freqency scaling on compaq nx9010

[Dominik Brodowski]

On Sun, Jan 09, 2005 at 09:33:08PM -0300, Thomas Eschenbacher wrote:
> The file "scaling_driver" told me it was "speedstep-smi".
> (which makes no sense to me, I have an ALI and no Intel chipset...)
> No idea what it really was, I saw no kernel message about
> speedstep or so.
> (ACPI version is 20040816)

Then you used the wrong speedstep-driver, AFAICS. It is only meant for
mobile Pentium III CPUs... I need to check why it didn't fail to load.

> I kicked out all speedstep stuff from my kernel config and now I see 
> 30590000 and 15960000 in 
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies -
> the same values as in my DSDT, using acpi-cpufreq as driver.
> 
> So what would be the advantage of speedstep over acpi-cpufreq ?
> Does it also switch core voltage or do other things?

The acpi-cpufreq driver (normally) also scales voltage, it may just be
slower than speedstep-ich or speedstep-centrino. However, it's ot faster or
slower than speedstep-smi.

	Dominik


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt