[PATCH] 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>
---
 drivers/cpufreq/cpufreq.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b696baeb249d..342bbee8d0e1 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 UINT_MAX;