regulator: Optimise out noop voltage changes

[pandora-kernel.git] / drivers / regulator / core.c

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a12cba3..ab419f8 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1697,10 +1697,17 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
 {
        struct regulator_dev *rdev = regulator->rdev;
-       int ret;
+       int ret = 0;
 
        mutex_lock(&rdev->mutex);
 
+       /* If we're setting the same range as last time the change
+        * should be a noop (some cpufreq implementations use the same
+        * voltage for multiple frequencies, for example).
+        */
+       if (regulator->min_uV == min_uV && regulator->max_uV == max_uV)
+               goto out;
+
        /* sanity check */
        if (!rdev->desc->ops->set_voltage &&
            !rdev->desc->ops->set_voltage_sel) {