cpufreq: Make sure target freq is within limits

__cpufreq_driver_target() must not pass target frequency beyond the
limits of current policy.

Today most of cpufreq platform drivers are doing this check in their
target routines. Why not move it to __cpufreq_driver_target()?
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cpufreq.c

@@ -1470,12 +1470,19 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			    unsigned int relation)
 {
 	int retval = -EINVAL;
+	unsigned int old_target_freq = target_freq;
 
 	if (cpufreq_disabled())
 		return -ENODEV;
 
-	pr_debug("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
-		target_freq, relation);
+	/* Make sure that target_freq is within supported range */
+	if (target_freq > policy->max)
+		target_freq = policy->max;
+	if (target_freq < policy->min)
+		target_freq = policy->min;
+
+	pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
+			policy->cpu, target_freq, relation, old_target_freq);
 
 	if (target_freq == policy->cur)
 		return 0;