diff options
| author | Zhuoyu Zhang <Zhuoyu.Zhang@freescale.com> | 2014-03-18 13:41:25 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-03-20 03:37:17 +0100 |
| commit | bfa709bc823fc32ee8dd5220d1711b46078235d8 (patch) | |
| tree | 04ef279dd3a82117c9282d77101744dbe3cafbe6 /drivers/cpufreq/ppc-corenet-cpufreq.c | |
| parent | 0b443ead714f0cba797a7f2476dd756f22b5421e (diff) | |
| download | linux-bfa709bc823fc32ee8dd5220d1711b46078235d8.tar.gz linux-bfa709bc823fc32ee8dd5220d1711b46078235d8.tar.bz2 linux-bfa709bc823fc32ee8dd5220d1711b46078235d8.zip | |
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 <Zhuoyu.Zhang@freescale.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/ppc-corenet-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/ppc-corenet-cpufreq.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 037949d575bd..3bd9123e7026 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -21,6 +21,7 @@ #include <linux/of.h> #include <linux/slab.h> #include <linux/smp.h> +#include <sysdev/fsl_soc.h> /** * 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; |