Pentium M 1.5GHz (Banias) CPU frequency scaling not working

[automatthias]

Hi,

I have an Fujitsu-Siemens Amilo Pro V2000D laptop. When running Slackware 9.0 on it, back in 2005, I had no problems with getting the CPU frequency scaling to work. Unfortunately, it doesn't want to work with Edgy Eft. My processor is:

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 9
model name : Intel(R) Celeron(R) M processor 1500MHz
stepping : 5
cpu MHz : 1499.868
cache size : 512 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 mce cx8 sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 tm pbe up
bogomips : 3001.80
clflush size : 64

So, basically, it's Pentium M 1.5GHz, Banias, (6, 9, 5). It should be supported by the speedstep-centrino kernel module. Here's a snippet from speedstep-centrino.c:

static const struct cpu_id cpu_ids[] = {
[CPU_BANIAS] = { 6, 9, 5 }, ← This matches my processor
[CPU_DOTHAN_A1] = { 6, 13, 1 },
[CPU_DOTHAN_A2] = { 6, 13, 2 },
[CPU_DOTHAN_B0] = { 6, 13, 6 },
[CPU_MP4HT_D0] = {15, 3, 4 },
[CPU_MP4HT_E0] = {15, 4, 1 },
};

When trying to insert the speedstep-centrino module:

sudo modprobe speedstep-centrino
FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.17-11-generic/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device

I also tried speedstep-ich and speedstep-smi and acpi-cpufreq: the same results.

To get some more debug info, I compiled vanilla 2.6.20 from kernel.org and passed cpufreq.debug=7 option. Trying to insert the module again:

sudo modprobe speedstep-centrino
FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.20/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): No such device

Here's my dmesg (grep -E (speed|freq)):

[ 11.983448] Kernel command line: root=/dev/hda5 ro cpufreq.debug=7 quiet splash
[ 13.278975] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
[ 5.984000] usb 1-1: new full speed USB device using uhci_hcd and address 2
[ 6.784000] usb 1-1: new full speed USB device using uhci_hcd and address 3
[ 7.180000] usb 2-1: new low speed USB device using uhci_hcd and address 2
[ 310.872000] speedstep-lib: x86: 6, model: 9
[ 310.872000] speedstep-ich: Intel(R) SpeedStep(TM) capable processor not found
[ 317.560000] acpi-cpufreq: acpi_cpufreq_init
[ 317.560000] acpi-cpufreq: acpi_cpufreq_early_init
[ 317.560000] cpufreq-core: trying to register driver acpi-cpufreq
[ 317.560000] cpufreq-core: adding CPU 0
[ 317.560000] acpi-cpufreq: acpi_cpufreq_cpu_init
[ 317.560000] cpufreq-core: initialization failed
[ 317.560000] cpufreq-core: no CPU initialized for driver acpi-cpufreq
[ 317.564000] cpufreq-core: unregistering CPU 0
[ 473.808000] speedstep-lib: x86: 6, model: 9
[ 473.808000] speedstep-ich: Intel(R) SpeedStep(TM) capable processor not found
[ 774.028000] speedstep-lib: x86: 6, model: 9
[ 774.028000] speedstep-smi: No supported Intel CPU detected.

What's interesting is that speedstep-centrino didn't output any messages in dmesg. All of the messages above come from the other modules.

I'm currently out of ideas: Where to look? How to debug? Any ideas?