How to get SpeedStep working on Coppermine-piix4-smi based ThinkPads
Contents
Foreword
APPLYING THIS HOWTO MAY MAKE YOU DUMB, CRASH YOUR CPU, YOUR MOTHERBOARD, MAKE YOUR GIRLFRIEND LEAVE YOU, OR MAYBE WORSE, USE IT AT YOUR OWN RISKS, I'M NOTHING OF A KERNEL HACKER, NEITHER A SMART GUY, THIS IS HOW I TRiED TO GET IT WORK, AND TILL NOW IT IS WORKING, MY PROPOSITION ARE ALMOST GUARANTED TO BE DUMB.
This HowTo is intended for people having trouble getting SpeedStep working via CpuFreq on their Coppermine CPU with a piix4 mainboard. ThinkPads known to have this configuration are the X20, X21, T20, T21, T22, TransNote and possibly A20m, A20p, A21e, A21p, A22e, A22m, A22p models. (EDIT: A21m reported to be frequency-scaling according to GNOME CPU Freq Applet in Ubuntu Dapper and perhaps already in Hoary)
The issue is that these CPUs do not repport correctly that they are SpeedStep capable.
This Document is under the GNU/GPL v2+ Licence.
My case
This is what i get: I have a x21 IBM ThinkPad, and when trying the SpeedStep implementation of 2.6 kernels i got:
$ sudo modprobe speedstep-smiFATAL: Error inserting speedstep_smi (/lib/modules/2.6.10-rc1-mm4-xa1/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-smi.ko): No such device
Rebooting with cpufreq.debug=7 ( 1 is for core, 2 is for ??, and 4 is for drivers, 7 = 1 + 2 + 4 ) gave:
$ sudo modprobe speedstep-smiFATAL: Error inserting speedstep_smi (/lib/modules/2.6.10-rc1-mm4-xa1/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-smi.ko): No such device$ sudo tail /var/log/syslog[...]Nov 11 19:54:20 localhost kernel: speedstep-lib: x86: 6, model: 8Nov 11 19:54:20 localhost kernel: speedstep-lib: Coppermine: MSR_IA32_EBL_CR_POWERON is 0x44080020, 0x0Nov 11 19:54:20 localhost kernel: speedstep-lib: Coppermine: MSR_IA32_PLATFORM ID is 0x0, 0x540000Nov 11 19:54:20 localhost kernel: speedstep-smi: No supported Intel CPU detected.
How to get it work
Note: to get this working on recent kernels you'll need:
CONFIG_X86_SPEEDSTEP_RELAXED_CHECK = y
Disable the speedstep-lib checks
$ sudo modprobe speedstep-lib relaxed_check=1$ sudo modprobe speedstep-smi
In Debian ( and probably with others, please confirm ), you can automate the module parmeters by creating a /etc/modprobe.d/speedstep-lib file with:
options speedstep-lib relaxed_check=1
And then, you may add these 2 lines to /etc/modules:
speedstep-lib speedstep-smi
Ubuntu (Edgy)
In Ubuntu I had to do following to make it work. Tested with T22.
$ sudo modprobe -r speedstep-lib speedstep-smi$ sudo modprobe speedstep-lib relaxed_check=1$ sudo modprobe speedstep-smi$ sudo modprobe cpufreq_userspace
With these cpufrequtils works fine.
Ubuntu (since 9.04)
Since the above modules are compiled in the kernel, this above methods does not work anymore
$ sudo killall powernowd$ sudo powernowd -q
et voilà.
Some people report that one should use grub and not grub2 (see [1]).
How to use it
How to make use of Dynamic Frequency Scaling
What's not working
On an X20, speedstep_smi messes up acpi and nvram. Best not to use it. See Kernel bug 6847
The speeds shown may be erroneous, which has dramatic consequances if you try to watch movies or applications that are (exact) time-depending (as the timer is all dizzy).
