Bug#499184: linux-2.6: acpi-cpufreq limits a Xeon 3.0GHz to 1.8GHz

[Aurelien Jarno <jarno@obs.univ-lyon1.fr>]

Package: linux-2.6
Version: 2.6.26-5
Severity: important

My machine has an Intel Xeon E3110 CPU running at 3.0GHz. When 
acpi-cpufreq is loaded, only two frequencies are available, 1.2GHz and
1.8GHz:

| # grep . /sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies
| /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies:1800000 1200000
| /sys/devices/system/cpu/cpu1/cpufreq/scaling_available_frequencies:1800000 1200000

This limits the maximum speed of the system to 1.8GHz when acpi-cpufreq
is loaded. Removing the module makes the CPU running back at 3.0GHz.

Here are the details from /proc/cpuinfo:

| processor       : 0
| vendor_id       : GenuineIntel
| cpu family      : 6
| model           : 23
| model name      : Intel(R) Xeon(R) CPU           E3110  @ 3.00GHz
| stepping        : 6
| cpu MHz         : 2992.499
| cache size      : 6144 KB
| physical id     : 0
| siblings        : 2
| core id         : 0
| cpu cores       : 2
| apicid          : 0
| initial apicid  : 0
| fpu             : yes
| fpu_exception   : yes
| cpuid level     : 10
| wp              : yes
| flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm
| bogomips        : 5989.46
| clflush size    : 64
| cache_alignment : 64
| address sizes   : 36 bits physical, 48 bits virtual
| power management:
| 
| processor       : 1
| vendor_id       : GenuineIntel
| cpu family      : 6
| model           : 23
| model name      : Intel(R) Xeon(R) CPU           E3110  @ 3.00GHz
| stepping        : 6
| cpu MHz         : 2992.499
| cache size      : 6144 KB
| physical id     : 0
| siblings        : 2
| core id         : 1
| cpu cores       : 2
| apicid          : 1
| initial apicid  : 1
| fpu             : yes
| fpu_exception   : yes
| cpuid level     : 10
| wp              : yes
| flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm
| bogomips        : 5985.04
| clflush size    : 64
| cache_alignment : 64
| address sizes   : 36 bits physical, 48 bits virtual
| power management:


-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.26-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash