Comment 16 for bug 52852

I notice the same behavior with the standard kernel from feisty and a gutsy 2.6.22 kernel from git with mactel patches applied. I have a Macbook Pro with a C2D processor.
The acpi-cpufreq module seems to work. It sets the correct values for the MSRs and a lower frequency is displayed. But if you use measurefreq from linux-phc you see that speedstepping doesn't work at all and the CPU works at 2.16 GHz (in my case) the whole time. speedstep-centrino doesn't work at all

FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.22-8-generic/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device