cpufreq: acpi-cpufreq: use cached frequency mapping when possible

A call to cpufreq_driver_resolve_freq will cache the mapping from
the desired target frequency to the frequency table index. If there
is a mapping for the desired target frequency then use it instead of
looking up the mapping again.

Signed-off-by: Steve Muckle <smuckle@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 11c9a07..297e912 100644 (file)
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -473,7 +473,10 @@ unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
        /*
         * Find the closest frequency above target_freq.
         */
-       index = cpufreq_table_find_index_dl(policy, target_freq);
+       if (policy->cached_target_freq == target_freq)
+               index = policy->cached_resolved_idx;
+       else
+               index = cpufreq_table_find_index_dl(policy, target_freq);
 
        entry = &policy->freq_table[index];
        next_freq = entry->frequency;