Bug 7591 - wrong cpu frequency after boot
wrong cpu frequency after boot
Product: ACPI
Classification: Unclassified
Component: Config-Processors
i386 Linux
: P2 high
Assigned To: acpi_config-processors
Depends on:
  Show dependency treegraph
Reported: 2006-11-29 01:20 UTC by Aleksei Lukin
Modified: 2007-02-13 00:18 UTC (History)
2 users (show)

See Also:
Kernel Version:
Tree: Mainline
Regression: ---


Description Aleksei Lukin 2006-11-29 01:20:46 UTC
Most recent kernel where this bug did *NOT* occur: none
Distribution: FC6, vanilla kernel, 2.6.19.rc6

Hardware Environment: Asus A6VM notebook, Intel 745 CPU
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 13
model name      : Intel(R) Pentium(R) M processor 1.80GHz
stepping        : 6

Software Environment: FC6, vanilla kernel

Problem Description: randomly, with 50/50 
probability /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq gives 600000 
instead of real 1800000. Default governor is "performance", compiled in. In 
boot process /etc/initd.d/cpufreq loads "p4-clockmod" driver and "ondemand" 
governor. "centrino" driver refused to load with this CPU.

Steps to reproduce:
Configure init scripts to load p4_clockmod and cpufreq_ondemand and boot on 
Comment 1 Chris Wedgwood 2006-11-30 08:38:16 UTC
this is very common with notebooks

the faster speeds become unavailable if the laptop gets hot (and maybe sometimes
the battery level low)

some notebooks (ie. thinkpads) have a bios setting where you can influence the
thermal balance (i forget what it's called)

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