[CPUFREQ] powernow-k8: Get transition latency from ACPI _PSS table

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At this time, the PowerNow! driver for K8 uses an experimentally
derived formula to calculate transition latency.  The value it
provides is orders of magnitude too large on modern systems.
This patch replaces the formula with ACPI _PSS latency values
for more accuracy and better performance.

I've tested it on two 2nd generation Opteron systems, a 3rd
generation Operton system, and a Turion X2 without seeing any
stability problems.

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>

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Mark Langsdorf 2009-02-03 17:46:43 +01:00 • committed by Dave Jones

parent 1ca3abdb6a

commit 732553e567

1 changed files with 22 additions and 6 deletions

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arch/x86/kernel/cpu/cpufreq/powernow-k8.c

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