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[CPUFREQ] powernow-k6: set transition latency value so ondemand governor can be used 

Set the transition latency to value smaller than CPUFREQ_ETERNAL so
governors other than "performance" work (like the "ondemand" one).

The value is found in "AMD PowerNow! Technology Platform Design Guide for
Embedded Processors" dated December 2000 (AMD doc #24267A). There is the
answer to one of FAQs on page 40 which states that suggested complete transition
period is 200 us.

Tested on K6-2+ CPU with K6-3 core (model 13, stepping 4).

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Krzysztof Helt 2009-10-25 19:45:57 +01:00 committed by Dave Jones
parent b8cbe7e82e
commit db2820dd54
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kernel/cpu/cpufreq/powernow-k6.c
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@ -164,7 +164,7 @@ static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
}
/* cpuinfo and default policy values */
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
policy->cpuinfo.transition_latency = 200000;
policy->cur = busfreq * max_multiplier;
result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);