| Date | Mon, 12 May 2014 02:34:01 +0200 | From | Willy Tarreau <> | Subject | [ 121/143] [CPUFREQ] powernow-k6: set transition latency value so ondemand |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ governor can be used
From: Krzysztof Helt <krzysztof.h1@wp.pl>
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> (cherry picked from commit db2820dd5445a44b4726f15a2bc89b9ded2503eb) [wt: in 2.6.32, we only need this one so that next series applies cleanly] Signed-off-by: Willy Tarreau <w@1wt.eu> --- arch/x86/kernel/cpu/cpufreq/powernow-k6.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c index f10dea4..cb01dac 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c @@ -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); -- 1.7.12.2.21.g234cd45.dirty
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