1 files changed, 43 insertions, 1 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 7a248dc8d2e2..8ed9b96518cf 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3797,6 +3797,16 @@ static int _regulator_do_set_suspend_voltage(struct regulator_dev *rdev,
 	return 0;
 }
 
+static int regulator_get_voltage_delta(struct regulator_dev *rdev, int uV)
+{
+	int current_uV = regulator_get_voltage_rdev(rdev);
+
+	if (current_uV < 0)
+		return current_uV;
+
+	return abs(current_uV - uV);
+}
+
 static int regulator_set_voltage_unlocked(struct regulator *regulator,
 					  int min_uV, int max_uV,
 					  suspend_state_t state)
@@ -3804,8 +3814,8 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
 	struct regulator_dev *rdev = regulator->rdev;
 	struct regulator_voltage *voltage = &regulator->voltage[state];
 	int ret = 0;
+	int current_uV, delta, new_delta;
 	int old_min_uV, old_max_uV;
-	int current_uV;
 
 	/* If we're setting the same range as last time the change
 	 * should be a noop (some cpufreq implementations use the same
@@ -3852,6 +3862,37 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
 		voltage->max_uV = old_max_uV;
 	}
 
+	if (rdev->constraints->max_uV_step > 0) {
+		/* For regulators with a maximum voltage step, reaching the desired
+		 * voltage might take a few retries.
+		 */
+		ret = regulator_get_voltage_delta(rdev, min_uV);
+		if (ret < 0)
+			goto out;
+
+		delta = ret;
+
+		while (delta > 0) {
+			ret = regulator_balance_voltage(rdev, state);
+			if (ret < 0)
+				goto out;
+
+			ret = regulator_get_voltage_delta(rdev, min_uV);
+			if (ret < 0)
+				goto out;
+
+			new_delta = ret;
+
+			/* check that voltage is converging quickly enough */
+			if (new_delta - delta > rdev->constraints->max_uV_step) {
+				ret = -EWOULDBLOCK;
+				goto out;
+			}
+
+			delta = new_delta;
+		}
+	}
+
 out:
 	return ret;
 }
@@ -5639,6 +5680,7 @@ static void regulator_remove_coupling(struct regulator_dev *rdev)
 				 ERR_PTR(err));
 	}
 
+	rdev->coupling_desc.n_coupled = 0;
 	kfree(rdev->coupling_desc.coupled_rdevs);
 	rdev->coupling_desc.coupled_rdevs = NULL;
 }