regulator: core: Optimize _regulator_do_set_voltage if voltage does not change

Optimize _regulator_do_set_voltage() for the case selector is equal to
old_selector. Since the voltage does not change, we don't need to call
set_voltage_sel() and set_voltage_time_sel() in this case.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c347fd0..7ec2ed6 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2185,8 +2185,11 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
                        best_val = rdev->desc->ops->list_voltage(rdev, ret);
                        if (min_uV <= best_val && max_uV >= best_val) {
                                selector = ret;
-                               ret = rdev->desc->ops->set_voltage_sel(rdev,
-                                                                      ret);
+                               if (old_selector == selector)
+                                       ret = 0;
+                               else
+                                       ret = rdev->desc->ops->set_voltage_sel(
+                                                               rdev, ret);
                        } else {
                                ret = -EINVAL;
                        }
@@ -2197,7 +2200,7 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 
        /* Call set_voltage_time_sel if successfully obtained old_selector */
        if (ret == 0 && _regulator_is_enabled(rdev) && old_selector >= 0 &&
-           rdev->desc->ops->set_voltage_time_sel) {
+           old_selector != selector && rdev->desc->ops->set_voltage_time_sel) {
 
                delay = rdev->desc->ops->set_voltage_time_sel(rdev,
                                                old_selector, selector);