ACPICA: Predefined name repair: automatically remove null package elements

This change will automatically remove embedded and trailing NULL
package elements from returned package objects that are defined
to containe a variable number of sub-packages. The driver is then
presented with a package with no null elements to deal with.
ACPICA BZ 819.

http://www.acpica.org/bugzilla/show_bug.cgi?id=819

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 14 insertions, 45 deletions

diff --git a/drivers/acpi/acpica/nspredef.c b/drivers/acpi/acpica/nspredef.c
index 239fa2f731c..d34fa59548f 100644
--- a/drivers/acpi/acpica/nspredef.c
+++ b/drivers/acpi/acpica/nspredef.c
@@ -231,9 +231,6 @@ acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
 	 * Note: Package may have been newly created by call above.
 	 */
 	if ((*return_object_ptr)->common.type == ACPI_TYPE_PACKAGE) {
-
-		/* TBD: For variable-length Packages, remove NULL elements here */
-
 		status = acpi_ns_check_package(data, return_object_ptr);
 		if (ACPI_FAILURE(status)) {
 			goto exit;
@@ -439,6 +436,13 @@ acpi_ns_check_package(struct acpi_predefined_data *data,
 			  data->pathname, package->ret_info.type,
 			  return_object->package.count));
 
+	/*
+	 * For variable-length Packages, we can safely remove all embedded
+	 * and trailing NULL package elements
+	 */
+	acpi_ns_remove_null_elements(data, package->ret_info.type,
+				     return_object);
+
 	/* Extract package count and elements array */
 
 	elements = return_object->package.elements;
@@ -692,53 +696,18 @@ acpi_ns_check_package_list(struct acpi_predefined_data *data,
 	union acpi_operand_object *sub_package;
 	union acpi_operand_object **sub_elements;
 	acpi_status status;
-	u8 non_trailing_null = FALSE;
 	u32 expected_count;
 	u32 i;
 	u32 j;
 
-	/* Validate each sub-Package in the parent Package */
-
+	/*
+	 * Validate each sub-Package in the parent Package
+	 *
+	 * NOTE: assumes list of sub-packages contains no NULL elements.
+	 * Any NULL elements should have been removed by earlier call
+	 * to acpi_ns_remove_null_elements.
+	 */
 	for (i = 0; i < count; i++) {
-		/*
-		 * Handling for NULL package elements. For now, we will simply allow
-		 * a parent package with trailing NULL elements. This can happen if
-		 * the package was defined to be longer than the initializer list.
-		 * This is legal as per the ACPI specification. It is often used
-		 * to allow for dynamic initialization of a Package.
-		 *
-		 * A future enhancement may be to simply truncate the package to
-		 * remove the trailing NULL elements.
-		 */
-		if (!(*elements)) {
-			if (!non_trailing_null) {
-
-				/* Ensure the remaining elements are all NULL */
-
-				for (j = 1; j < (count - i + 1); j++) {
-					if (elements[j]) {
-						non_trailing_null = TRUE;
-					}
-				}
-
-				if (!non_trailing_null) {
-
-					/* Ignore the trailing NULL elements */
-
-					return (AE_OK);
-				}
-			}
-
-			/* There are trailing non-null elements, issue warning */
-
-			ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
-					      data->node_flags,
-					      "Found NULL element at package index %u",
-					      i));
-			elements++;
-			continue;
-		}
-
 		sub_package = *elements;
 		sub_elements = sub_package->package.elements;