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 239fa2f731ca..d34fa59548f7 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;