From bfa709bc823fc32ee8dd5220d1711b46078235d8 Mon Sep 17 00:00:00 2001 From: Zhuoyu Zhang Date: Tue, 18 Mar 2014 13:41:25 +0800 Subject: [PATCH] cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs According to the data provided by HW Team, at least 12 internal platform clock cycles are required to stabilize a DFS clock switch on FSL e500mc Socs. This patch replaces the CPUFREQ_ETERNAL with appropriate HW clock transition latency to make DFS governors work normally on Freescale e500mc boards. Signed-off-by: Zhuoyu Zhang Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/ppc-corenet-cpufreq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 037949d..3bd9123 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -21,6 +21,7 @@ #include #include #include +#include /** * struct cpu_data - per CPU data struct @@ -205,7 +206,8 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) for_each_cpu(i, per_cpu(cpu_mask, cpu)) per_cpu(cpu_data, i) = data; - policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + policy->cpuinfo.transition_latency = + (12 * NSEC_PER_SEC) / fsl_get_sys_freq(); of_node_put(np); return 0; -- 2.7.4