Paul wrote:
> I have a mobile Pentium 4 (538) 1mb L2 cache supposedly with enhanced
> speedstep technology. how how do i get it working? I want to lower
> frequency AND voltage. ive tried cpudyn, powernowd, and just cant seem
> to get it working. Im using kernel 2.6.11 and here is part of my
> config: [ ... ]
>
> #
> # CPUFreq processor drivers
> #
> CONFIG_X86_ACPI_CPUFREQ=m

Did you modprobe the resulting module ?

Before you set up cpudyn or powernowd you might want to try the
low-level interface under /sys/devices/system/cpu/*/cpufreq/ .
(If the pseudo-files aren't there, it's a sure sign that you didn't
modprobe your module).

The Gentoo people documented this (and more) at
http://www.gentoo.org/doc/en/power-management-guide.xml . The full
document is of course specific to their distribution, but the short
part about the /sys interface is determined by the kernel, hence
identical on all distributions.

You may also want to look at /var/log/dmesg (or the equivalent on
your distribution). Mine says:

powernow: PowerNOW! Technology present. Can scale: frequency and voltage.

I mention this because the /sys/ interface uses only frequency,
not voltage. However, because of the dmesg I believe that the
voltage is automatically reduced at the lower cpu frequencies.


--
pa at panix dot com

Pierre Asselin wrote:
> Paul wrote:
>
>>I have a mobile Pentium 4 (538) 1mb L2 cache supposedly with enhanced
>>speedstep technology. how how do i get it working? I want to lower
>>frequency AND voltage. ive tried cpudyn, powernowd, and just cant seem
>>to get it working. Im using kernel 2.6.11 and here is part of my
>>config: [ ... ]
>>
>>#
>># CPUFreq processor drivers
>>#
>>CONFIG_X86_ACPI_CPUFREQ=m
>
>
> Did you modprobe the resulting module ?
>
> Before you set up cpudyn or powernowd you might want to try the
> low-level interface under /sys/devices/system/cpu/*/cpufreq/ .
> (If the pseudo-files aren't there, it's a sure sign that you didn't
> modprobe your module).
>
> The Gentoo people documented this (and more) at
> http://www.gentoo.org/doc/en/power-management-guide.xml . The full
> document is of course specific to their distribution, but the short
> part about the /sys interface is determined by the kernel, hence
> identical on all distributions.
>
> You may also want to look at /var/log/dmesg (or the equivalent on
> your distribution). Mine says:
>
> powernow: PowerNOW! Technology present. Can scale: frequency and voltage.
>
> I mention this because the /sys/ interface uses only frequency,
> not voltage. However, because of the dmesg I believe that the
> voltage is automatically reduced at the lower cpu frequencies.
>
>


I do have the /sys interface files. In the file scaling_driver there is
p4-clockmod listed. I run dmesg and this is what I get:

p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available

I want the speedstep-centrino wroking that modifies the voltage also. I
have some screenshots of what im talking about. Under Windows the
voltage decreases as shown here:
http://plaza.ufl.edu/redboots/files/...e_throttle.jpg

With fullpower the voltage and frequency are at their max.
http://plaza.ufl.edu/redboots/files/no_throttle.jpg


And there are only two voltages and frequencies.
I just thought of something, if I compile the kernel with Pentium M
supprt and not Pentium4 support do you think it would work?

--
Paul Johnson
Graduate Student - Mechanical Engineering
University of Florida - Gainesville, Fl
http://plaza.ufl.edu/redboots

Reclaim Your Inbox!
http://www.mozilla.org/products/thunderbird

Paul wrote:
> Pierre Asselin wrote:
> > Paul wrote:
> >
> >>I have a mobile Pentium 4 (538) 1mb L2 cache supposedly with enhanced
> >>speedstep technology. [ ... ]

> [ ... ]
> >>CONFIG_X86_ACPI_CPUFREQ=m

> [ ... ]
> I do have the /sys interface files. In the file scaling_driver there is
> p4-clockmod listed. I run dmesg and this is what I get:

> p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available

Okay, you seem to have two low-level cpufreq drivers enabled:
X86_ACPI_CPUFREQ as a module, and X86_P4_CLOCKMOD, either as a
module or built-in. You are in fact using X86_P4_CLOCKMOD.
According to the dmesg, it is at least partially working.

If your P4_CLOCKMOD is in as a module, you can try to "modprobe -r"
it and later modprobe the ACPI_CPUFREQ module. I don't know what
the module names are, you'll have to guess by looking under
/lib/modules.


> I want the speedstep-centrino wroking that modifies the voltage also.

But you don't have a Centrino, you say you have a P4. The Centrino
is a marketing brand that represents a Pentium M (not mobile P4) plus a
specific chipset plus a specific wireless card. What does
/proc/cpuinfo contain ?

The Intel website uses the phrase "Enhanced Intel SpeedStep" with
both processors, but it's hard to say if they're the same thing ...

> I just thought of something, if I compile the kernel with Pentium M
> supprt and not Pentium4 support do you think it would work?

See above. Well, you could try
X86_ACPI_CPUFREQ=m
X86_P4_CLOCKMOD=m
X86_SPEEDSTEP_CENTRINO=m
X86_SPEEDSTEP_CENTRINO_TABLE=y
to compile as modules all the drivers that have a chance, modprobe
them in and out one by one, and keep the one that works best.

Note that even if you find the right module and your CPU voltage
is controlled, Linux may not show that to you. At least, I don't
see a way to read the voltage on my unit.


--
pa at panix dot com

Pierre Asselin wrote:
> Paul wrote:
>
>>Pierre Asselin wrote:
>>
>>>Paul wrote:
>>>
>>>
>>>>I have a mobile Pentium 4 (538) 1mb L2 cache supposedly with enhanced
>>>>speedstep technology. [ ... ]
>
>
>>[ ... ]
>>
>>>>CONFIG_X86_ACPI_CPUFREQ=m
>
>
>>[ ... ]
>>I do have the /sys interface files. In the file scaling_driver there is
>>p4-clockmod listed. I run dmesg and this is what I get:
>
>
>>p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available
>
>
> Okay, you seem to have two low-level cpufreq drivers enabled:
> X86_ACPI_CPUFREQ as a module, and X86_P4_CLOCKMOD, either as a
> module or built-in. You are in fact using X86_P4_CLOCKMOD.
> According to the dmesg, it is at least partially working.
>
> If your P4_CLOCKMOD is in as a module, you can try to "modprobe -r"
> it and later modprobe the ACPI_CPUFREQ module. I don't know what
> the module names are, you'll have to guess by looking under
> /lib/modules.
>
>
>
>>I want the speedstep-centrino wroking that modifies the voltage also.
>
>
> But you don't have a Centrino, you say you have a P4. The Centrino
> is a marketing brand that represents a Pentium M (not mobile P4) plus a
> specific chipset plus a specific wireless card. What does
> /proc/cpuinfo contain ?
>
> The Intel website uses the phrase "Enhanced Intel SpeedStep" with
> both processors, but it's hard to say if they're the same thing ...
>
>
>>I just thought of something, if I compile the kernel with Pentium M
>>supprt and not Pentium4 support do you think it would work?
>
>
> See above. Well, you could try
> X86_ACPI_CPUFREQ=m
> X86_P4_CLOCKMOD=m
> X86_SPEEDSTEP_CENTRINO=m
> X86_SPEEDSTEP_CENTRINO_TABLE=y
> to compile as modules all the drivers that have a chance, modprobe
> them in and out one by one, and keep the one that works best.
>
> Note that even if you find the right module and your CPU voltage
> is controlled, Linux may not show that to you. At least, I don't
> see a way to read the voltage on my unit.
>
>

Ok, I guess Im just really confused about everything. Sorry. Im
confused about the low level kernel cpufreq drivers. I tried reading
the kernel documentation but its a little above me at this moment. For
my mobile P4, do I just need acpi-cpufreq or speedstep-ich? From there
Ill compile what I need and not anything extra. p4-clockmod is
definately not what Im looking for, only changes frequency.
Thanks
Paul


--
Paul Johnson
Graduate Student - Mechanical Engineering
University of Florida - Gainesville, Fl
http://plaza.ufl.edu/redboots

Reclaim Your Inbox!
http://www.mozilla.org/products/thunderbird

Paul wrote:

> Ok, I guess Im just really confused about everything. Sorry. Im
> confused about the low level kernel cpufreq drivers. I tried reading
> the kernel documentation but its a little above me at this moment. For
> my mobile P4, do I just need acpi-cpufreq or speedstep-ich? From there
> Ill compile what I need and not anything extra. p4-clockmod is
> definately not what Im looking for, only changes frequency.

How can you tell that it's not changing the voltage?

It is confusing. Like I said, compile them all as modules and try
them one by one, watching the dmesg output as you modprobe them in
and out. One or more of the modules might say "Hi, I can change
the frequency and the voltage". Note that as far as I know the
kernel has no interface to tell you the voltage, unlike for the
frequency.

Of those drivers, the ACPI_CPUFREQ should be processor-independent.
This is because ACPI provides a standardized interface to power and
performance management. The vendor is supposed to supply subroutines
that work on their processor/chipset/whatever and Linux will be
able to call them.

--
pa at panix dot com