1 files changed, 38 insertions, 29 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 9bd1b6044b55..95fedbdf4fb8 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -266,6 +266,35 @@ static int acpi_power_off_device(acpi_handle handle)
 	return result;
 }
 
+static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
+{
+	int i;
+
+	for (i = num_res - 1; i >= 0 ; i--)
+		acpi_power_off_device(list->handles[i]);
+}
+
+static void acpi_power_off_list(struct acpi_handle_list *list)
+{
+	__acpi_power_off_list(list, list->count);
+}
+
+static int acpi_power_on_list(struct acpi_handle_list *list)
+{
+	int result = 0;
+	int i;
+
+	for (i = 0; i < list->count; i++) {
+		result = acpi_power_on(list->handles[i]);
+		if (result) {
+			__acpi_power_off_list(list, i);
+			break;
+		}
+	}
+
+	return result;
+}
+
 /**
  * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
  *                          ACPI 3.0) _PSW (Power State Wake)
@@ -458,10 +487,7 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 
 int acpi_power_transition(struct acpi_device *device, int state)
 {
-	int result = 0;
-	struct acpi_handle_list *cl = NULL;	/* Current Resources */
-	struct acpi_handle_list *tl = NULL;	/* Target Resources */
-	int i = 0;
+	int result;
 
 	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
 		return -EINVAL;
@@ -473,37 +499,20 @@ int acpi_power_transition(struct acpi_device *device, int state)
 	    || (device->power.state > ACPI_STATE_D3))
 		return -ENODEV;
 
-	cl = &device->power.states[device->power.state].resources;
-	tl = &device->power.states[state].resources;
-
 	/* TBD: Resources must be ordered. */
 
 	/*
 	 * First we reference all power resources required in the target list
-	 * (e.g. so the device doesn't lose power while transitioning).
+	 * (e.g. so the device doesn't lose power while transitioning).  Then,
+	 * we dereference all power resources used in the current list.
 	 */
-	for (i = 0; i < tl->count; i++) {
-		result = acpi_power_on(tl->handles[i]);
-		if (result)
-			goto end;
-	}
+	result = acpi_power_on_list(&device->power.states[state].resources);
+	if (!result)
+		acpi_power_off_list(
+			&device->power.states[device->power.state].resources);
 
-	/*
-	 * Then we dereference all power resources used in the current list.
-	 */
-	for (i = 0; i < cl->count; i++) {
-		result = acpi_power_off_device(cl->handles[i]);
-		if (result)
-			goto end;
-	}
-
-     end:
-	if (result)
-		device->power.state = ACPI_STATE_UNKNOWN;
-	else {
-	/* We shouldn't change the state till all above operations succeed */
-		device->power.state = state;
-	}
+	/* We shouldn't change the state unless the above operations succeed. */
+	device->power.state = result ? ACPI_STATE_UNKNOWN : state;
 
 	return result;
 }