cpufreq: Fix policy getting stuck when user & kernel min/max don't overlap

Every __cpufreq_set_policy starts with checking the new policy min/max has
some overlap with the current policy min/max. This works out fine until we
end up with the policy min/max being set to a range that doesn't overlap
with the user policy min/max. Once we get into this situation, the check at
the start of __cpufreq_set_policy fails and prevents us from getting out of
this state.

This only happens when one of the CPUFREQ_ADJUST/CPUFREQ_INCOMPATIBLE
notifiers called inside __cpufreq_set_policy pick a min/max outside the
range of user policy min/max.

The real intent of the check at the start of __cpufreq_set_policy is to
make sure userspace can't set user policy min > user policy max. Since
__cpufreq_set_policy always gets called only with current user policy
min/max except when the actual user space policy min/max is changed, we can
fix the issue by simply checking the new policy min/max against current
user policy min/max.

Change-Id: Iaac805825e64d7985c41fb9052bd96baacdf3d6f
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>

Author: Saravana Kannan

drivers/cpufreq/cpufreq.c

@@ -1751,7 +1751,8 @@ static int __cpufreq_set_policy(struct cpufreq_policy *data,
 	memcpy(&policy->cpuinfo, &data->cpuinfo,
 				sizeof(struct cpufreq_cpuinfo));
 
-	if (policy->min > data->max || policy->max < data->min) {
+	if (policy->min > data->user_policy.max
+		|| policy->max < data->user_policy.min) {
 		ret = -EINVAL;
 		goto error_out;
 	}