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authorKrzysztof Helt <krzysztof.h1@wp.pl>2009-10-25 19:45:57 +0100
committerStefan Bader <stefan.bader@canonical.com>2014-05-20 16:35:13 +0200
commit8b210feac7b6b4b53d46169f2fc934436e253f85 (patch)
tree3f3ef5cab4c2d4a20c2b2c62e4d1dd52b8eeb16d
parentfec05a717942162d7f19864ea01950285739606b (diff)
downloadlinux-2.6.32.y-drm33.z-8b210feac7b6b4b53d46169f2fc934436e253f85.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> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
-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 f10dea409f40c3..cb01dac267d3de 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);