cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index()

The handlers provided by cpufreq core are sufficient for resolving the
frequency for drivers providing ->target_index(), as the core already
has the frequency table and so ->resolve_freq() isn't required for such
platforms.

This patch disallows drivers with ->target_index() callback to use the
->resolve_freq() callback.

Also, it fixes a potential kernel crash for drivers providing ->target()
but no ->resolve_freq().

Fixes: e3c062360870 "cpufreq: add cpufreq_driver_resolve_freq()"
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b696baeb249d..3ef9be3965ff 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -507,12 +507,20 @@ unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
 {
         target_freq = clamp_val(target_freq, policy->min, policy->max);
         policy->cached_target_freq = target_freq;
+
+        if (cpufreq_driver->target_index) {
+                int idx;
+
+                idx = cpufreq_frequency_table_target(policy, target_freq,
+                                                     CPUFREQ_RELATION_L);
+                policy->cached_resolved_idx = idx;
+                return policy->freq_table[idx].frequency;
+        }
+
         if (cpufreq_driver->resolve_freq)
                 return cpufreq_driver->resolve_freq(policy, target_freq);
-        policy->cached_resolved_idx =
-                cpufreq_frequency_table_target(policy, target_freq,
-                                               CPUFREQ_RELATION_L);
-        return policy->freq_table[policy->cached_resolved_idx].frequency;
+
+        return target_freq;
 }
 
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