[PATCH 1/2] ACPI / ACPICA: refactor acpi_evaluate_object() to reduce nesting if

[Hanjun Guo <hanjun.guo@linaro.org>]

acpi_evaluate_object() has nesting if judgement to make code a little
bit complicated, refactor it to make things simple.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/acpi/acpica/nsxfeval.c |  104 +++++++++++++++++++---------------------
 1 file changed, 50 insertions(+), 54 deletions(-)

diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
index 1f0c28b..a1b0b88 100644
--- a/drivers/acpi/acpica/nsxfeval.c
+++ b/drivers/acpi/acpica/nsxfeval.c
@@ -370,68 +370,64 @@ acpi_evaluate_object(acpi_handle handle,
 	 * If we are expecting a return value, and all went well above,
 	 * copy the return value to an external object.
 	 */
-	if (return_buffer) {
-		if (!info->return_object) {
-			return_buffer->length = 0;
-		} else {
-			if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
-			    ACPI_DESC_TYPE_NAMED) {
-				/*
-				 * If we received a NS Node as a return object, this means that
-				 * the object we are evaluating has nothing interesting to
-				 * return (such as a mutex, etc.)  We return an error because
-				 * these types are essentially unsupported by this interface.
-				 * We don't check up front because this makes it easier to add
-				 * support for various types at a later date if necessary.
-				 */
-				status = AE_TYPE;
-				info->return_object = NULL;	/* No need to delete a NS Node */
-				return_buffer->length = 0;
-			}
+	if (!return_buffer)
+		goto out;
 
-			if (ACPI_SUCCESS(status)) {
+	if (!info->return_object) {
+		return_buffer->length = 0;
+		goto out;
+	}
 
-				/* Dereference Index and ref_of references */
+	if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
+		ACPI_DESC_TYPE_NAMED) {
+		/*
+		 * If we received a NS Node as a return object, this means that
+		 * the object we are evaluating has nothing interesting to
+		 * return (such as a mutex, etc.)  We return an error because
+		 * these types are essentially unsupported by this interface.
+		 * We don't check up front because this makes it easier to add
+		 * support for various types at a later date if necessary.
+		 */
+		status = AE_TYPE;
+		info->return_object = NULL;	/* No need to delete a NS Node */
+		return_buffer->length = 0;
+	}
 
-				acpi_ns_resolve_references(info);
+	if (ACPI_FAILURE(status))
+		goto out;
 
-				/* Get the size of the returned object */
+	/* Dereference Index and ref_of references */
 
-				status =
-				    acpi_ut_get_object_size(info->return_object,
-							    &buffer_space_needed);
-				if (ACPI_SUCCESS(status)) {
-
-					/* Validate/Allocate/Clear caller buffer */
-
-					status =
-					    acpi_ut_initialize_buffer
-					    (return_buffer,
-					     buffer_space_needed);
-					if (ACPI_FAILURE(status)) {
-						/*
-						 * Caller's buffer is too small or a new one can't
-						 * be allocated
-						 */
-						ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-								  "Needed buffer size %X, %s\n",
-								  (u32)
-								  buffer_space_needed,
-								  acpi_format_exception
-								  (status)));
-					} else {
-						/* We have enough space for the object, build it */
-
-						status =
-						    acpi_ut_copy_iobject_to_eobject
-						    (info->return_object,
-						     return_buffer);
-					}
-				}
-			}
+	acpi_ns_resolve_references(info);
+
+	/* Get the size of the returned object */
+
+	status = acpi_ut_get_object_size(info->return_object,
+						&buffer_space_needed);
+	if (ACPI_SUCCESS(status)) {
+
+		/* Validate/Allocate/Clear caller buffer */
+
+		status = acpi_ut_initialize_buffer(return_buffer,
+							buffer_space_needed);
+		if (ACPI_FAILURE(status)) {
+			/*
+			 * Caller's buffer is too small or a new one can't
+			 * be allocated
+			 */
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					"Needed buffer size %X, %s\n",
+					(u32)buffer_space_needed,
+					 acpi_format_exception(status)));
+		} else {
+			/* We have enough space for the object, build it */
+
+			status = acpi_ut_copy_iobject_to_eobject(
+					info->return_object, return_buffer);
 		}
 	}
 
+out:
 	if (info->return_object) {
 		/*
 		 * Delete the internal return object. NOTE: Interpreter must be
-- 
1.7.9.5