From: Krzysztof Helt <krzysztof.h1@xxxxx> 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@xxxxx> --- This is the second version of the patch with added comment into the source code. arch/x86/kernel/cpu/cpufreq/powernow-k6.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c index f10dea4..15f84a6 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c @@ -163,8 +163,15 @@ static int powernow_k6_cpu_init(struct cpufreq_policy *policy) clock_ratio[i].frequency = busfreq * f; } - /* cpuinfo and default policy values */ - policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + /* + * cpuinfo and default policy values + * + * 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. + */ + policy->cpuinfo.transition_latency = 200000; policy->cur = busfreq * max_multiplier; result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio); -- 1.6.4 -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
