Acpi-cpufreq supplies wrong scaling frequencies

Question

I have a problem with speedstepping on my Acer Extensa 3000.
CPU is a Pentium M 1.50GHz
the kernel modul 'acpi_cpufreq' supplies wrong available stepping frequencies.
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
1600000 1400000 1200000 800000 600000
I use a fixed DSDT table and the newst availabe BIOS Version.
Also I tried it with the original DSDT and the other (only 2 versions are available) BIOS.
Same results.
If I unload the acpi_cpufreq module, the frequency jumps to the CPUs "normal" freq. 1499MHz
(I also noticed a strange behavior: sometimes the freq jumps to values about 1700MHz or 673MHz if I unload the modul)
`dmesg | grep -i acpi` shows no errors.
cpuinfo
cat /proc/cpuinfo processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 13
model name : Intel(R) Pentium(R) M processor 1.50GHz
stepping : 8
cpu MHz : 600.000
cache size : 2048 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx up bts est tm2
bogomips : 1285.77
clflush size : 64
I use the Arch stock kernel, but I don't think it's ArchLinux specific.
I had the same problems under Gentoo and also with Vanilla kernels.
Should I file a bugreport  to the kernel.org bugtracker or is it related to a maybe buggy BIOS?
BTW:
I think the Acer Extensa series was only sold in Germany.
The Hardware of my Extensa 3000 seems to be similar to the Travlemate 4000. They use the same BIOS.
Last edited by SiD (2008-04-01 11:14:09)

Answer 1

My problem is that acpi_cpufreq reports the wrong freqs for my CPU.
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
1600000 1400000 1200000 800000 600000
As you can see the max. available freq. acpi_cpufreq reports is 1.6GHz but my CPU is only a 1.50GHz Pentium M.
So I have to set the max.scaling freq to 1.4GHz on boot. If I don't the CPU runs at 1.6GHz and gets to hot.
It's not related to the AC-Adapter.
So,
if I want to use Speedstepping I have to run the 1.5GHz at 1.4GHz.
edit:
@Ashren
Sounds to me like your PC switches to some "powersave mode" if you unplug the AC-Adapter and don't switch back if it is pluged in again. Maybe there is a BIOS option that do that? In my BIOS e.g. there is an option that dims the display if I unplug the AC-Adapter.
Last edited by SiD (2008-04-02 20:44:47)