regulator: Only notify voltage changes when they succeed

Currently we notify a voltage change whenever we exit set_voltage(),
even if the change failed for some reason (eg, a constraints issue).
This shouldn't cause any substantial ill effects but is wasteful as
listeners get notified on noops. Fix this by moving the notification
into _do_set_voltage() and only notifying if we don't return an error.

Reported-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a0579f069002..3d72cc8e2f3e 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1667,6 +1667,10 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
                 ret = -EINVAL;
         }
 
+        if (ret == 0)
+                _notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE,
+                                     NULL);
+
         trace_regulator_set_voltage_complete(rdev_get_name(rdev), selector);
 
         return ret;
@@ -1718,7 +1722,6 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
         ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
 
 out:
-        _notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, NULL);
         mutex_unlock(&rdev->mutex);
         return ret;
 }