acpi-cpufreq does not recognize all frequencies for E8500 CPU
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Expired
|
Undecided
|
Unassigned | ||
Bug Description
Binary package hint: linux-image-generic
I have E8500 Intel Core2Duo CPU:
vampirella:~ $ grep model /proc/cpuinfo
model : 23
model name : Intel(R) Core(TM)2 Duo CPU E8500 @ 3.16GHz
...
It seems that kernel acpi cpufreq module detects and uses only lowest and highest frequency, instead one for each frequency multiplier -- CPU stepping supports following: 6x333, 7x333, 8x333, 9x333 and 9.5x333.
The relevant output follows:
vampirella:~ $ cat /sys/devices/
3166000 2000000
vampirella:~ $ cat /sys/devices/
From : To
: 3166000 2000000
3166000: 0 62
2000000: 61 0
vampirella:~ $ cpufreq-info
cpufrequtils 002: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to <email address hidden>, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0
hardware limits: 2.00 GHz - 3.17 GHz
available frequency steps: 3.17 GHz, 2.00 GHz
available cpufreq governors: userspace, powersave, ondemand, conservative, performance
current policy: frequency should be within 2.00 GHz and 3.17 GHz.
current CPU frequency is 2.00 GHz.
...
CPU is not overclocked and frequency scaling works fine in Windows XP/Vista. MBO is Gigabyte GA-P35-DS3 with latest F14a BIOS and CPU is recognized correctly. Gigabyte's MIT (auto-overclocking) is not enabled.
Ondemand stepping works generally OK, but as I said -- frequency jumps from lowest to highest speed.
This is a real kernel issue, and therefore should be reported against the linux package. Shifting there for visibility.