regulator: core: Use map_voltage_linear() if list_voltage_linear() is in use and nothing is set

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 8521e0d..3cbe312 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2118,12 +2118,18 @@
 		ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV,
 						   &selector);
 	} else if (rdev->desc->ops->set_voltage_sel) {
-		if (rdev->desc->ops->map_voltage)
+		if (rdev->desc->ops->map_voltage) {
 			ret = rdev->desc->ops->map_voltage(rdev, min_uV,
 							   max_uV);
-		else
-			ret = regulator_map_voltage_iterate(rdev, min_uV,
-							    max_uV);
+		} else {
+			if (rdev->desc->ops->list_voltage ==
+			    regulator_list_voltage_linear)
+				ret = regulator_map_voltage_linear(rdev,
+								min_uV, max_uV);
+			else
+				ret = regulator_map_voltage_iterate(rdev,
+								min_uV, max_uV);
+		}
 
 		if (ret >= 0) {
 			selector = ret;