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authorKrzysztof Helt <krzysztof.h1@wp.pl>2009-10-25 19:45:57 +0100
committerWilly Tarreau <w@1wt.eu>2014-05-19 07:54:25 +0200
commit9d73a68445d6a36c9fabd96906663c5db4a685ff (patch)
treead70deb24436313e3048bdbacd68052928010b6c
parent3ae3f8b7150ecde872a4a033127218f43c75d4b6 (diff)
downloadlinux-linaro-stable-9d73a68445d6a36c9fabd96906663c5db4a685ff.tar.gz
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> (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>
-rw-r--r--arch/x86/kernel/cpu/cpufreq/powernow-k6.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c
index f10dea409f40..cb01dac267d3 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);