Re: Thermal problems with newer kernels

From: Andrew Watts
Date: Sat Jan 31 2009 - 03:09:11 EST


Robert Hancock wrote:
>Andrew Watts wrote:
>> Dear Kernel Gurus:
>>
>> Below is a problem that I am unable to explain along with relevant(?) in
>> fo. Please leti me know if I should provide additional debugging
>> information. Thanks in advance for your assistance!
>>
>> -Andy
>>
>> [1] Problem: HP Pavilion zv5000 laptop idle temp is 17 degrees higher
>> when running most recent kernels (57C versus 40C).
>>
>> [2] Brief Description
>>
>> Newer kernels (noticed starting with 2.6.27.3 but could have started any
>> time past 2.6.26.7) result in a much higher idle CPU temp. Physical
>> temperature reading of exhaust from primary cooling fan and the regular
>> triggering of secondary cooling fan confirms this (it is not a readout
>> scaling issue). The kernels and temps below:
>>
>> 2.6.26.7 Idle temp 40C
>> 2.6.27.3 Idle temp 57C
>> 2.6.28 Idle temp 57C
>>
>> The only third party kernel module installed that is not part of the
>> official kernel source is: madwifi-ng. However, the problem occurs even
>> when this module is not loaded.
>>
>> The .config file used for the newer kernels was imported from the
>> working 2.6.26.7 .config file.
>
>CPU frequency scaling not working perhaps? What's your dmesg output from
>bootup look like? Is the acpi-cpufreq driver being loaded?

I thought I had checked this but...the problem goes away with "nolapic" (i
had configured lapic into previous kernels, even though a uniprocessor,
because it solved minor IRQ issues). Broken HP APIC? I fixed the IRQ issue
by forcing IRQ balancing. Interesting that this starts with 2.6.27.x.

Many thanks for your response.





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