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>

3 files changed, 65 insertions, 78 deletions

diff --git a/drivers/acpi/acpica/acnamesp.h b/drivers/acpi/acpica/acnamesp.h
index 14cef45bd6c4..61edb156e8d0 100644
--- a/drivers/acpi/acpica/acnamesp.h
+++ b/drivers/acpi/acpica/acnamesp.h
@@ -296,6 +296,11 @@ acpi_ns_complex_repairs(struct acpi_predefined_data *data,
                         acpi_status validate_status,
                         union acpi_operand_object **return_object_ptr);
 
+void
+acpi_ns_remove_null_elements(struct acpi_predefined_data *data,
+                             u8 package_type,
+                             union acpi_operand_object *obj_desc);
+
 /*
  * nssearch - Namespace searching and entry
  */
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;
 
diff --git a/drivers/acpi/acpica/nsrepair2.c b/drivers/acpi/acpica/nsrepair2.c
index e7373eb6cfa5..f13691c1cca5 100644
--- a/drivers/acpi/acpica/nsrepair2.c
+++ b/drivers/acpi/acpica/nsrepair2.c
@@ -45,6 +45,7 @@
 #include <acpi/acpi.h>
 #include "accommon.h"
 #include "acnamesp.h"
+#include "acpredef.h"
 
 #define _COMPONENT          ACPI_NAMESPACE
 ACPI_MODULE_NAME("nsrepair2")
@@ -93,9 +94,6 @@ acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
                           u8 sort_direction, char *sort_key_name);
 
 static acpi_status
-acpi_ns_remove_null_elements(union acpi_operand_object *package);
-
-static acpi_status
 acpi_ns_sort_list(union acpi_operand_object **elements,
                   u32 count, u32 index, u8 sort_direction);
 
@@ -456,25 +454,10 @@ acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
         }
 
         /*
-         * Detect any NULL package elements and remove them from the
-         * package.
-         *
-         * TBD: We may want to do this for all predefined names that
-         * return a variable-length package of packages.
+         * 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.
          */
-        status = acpi_ns_remove_null_elements(return_object);
-        if (status == AE_NULL_ENTRY) {
-                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
-                                  "%s: NULL elements removed from package\n",
-                                  data->pathname));
-
-                /* Exit if package is now zero length */
-
-                if (!return_object->package.count) {
-                        return (AE_NULL_ENTRY);
-                }
-        }
-
         outer_elements = return_object->package.elements;
         outer_element_count = return_object->package.count;
         if (!outer_element_count) {
@@ -544,36 +527,63 @@ acpi_ns_check_sorted_list(struct acpi_predefined_data *data,
  *
  * FUNCTION:    acpi_ns_remove_null_elements
  *
- * PARAMETERS:  obj_desc            - A Package object
+ * PARAMETERS:  Data                - Pointer to validation data structure
+ *              package_type        - An acpi_return_package_types value
+ *              obj_desc            - A Package object
  *
- * RETURN:      Status. AE_NULL_ENTRY means that one or more elements were
- *              removed.
+ * RETURN:      None.
  *
- * DESCRIPTION: Remove all NULL package elements and update the package count.
+ * DESCRIPTION: Remove all NULL package elements from packages that contain
+ *              a variable number of sub-packages.
  *
  *****************************************************************************/
 
-static acpi_status
-acpi_ns_remove_null_elements(union acpi_operand_object *obj_desc)
+void
+acpi_ns_remove_null_elements(struct acpi_predefined_data *data,
+                             u8 package_type,
+                             union acpi_operand_object *obj_desc)
 {
         union acpi_operand_object **source;
         union acpi_operand_object **dest;
-        acpi_status status = AE_OK;
         u32 count;
         u32 new_count;
         u32 i;
 
+        ACPI_FUNCTION_NAME(ns_remove_null_elements);
+
+        /*
+         * PTYPE1 packages contain no subpackages.
+         * PTYPE2 packages contain a variable number of sub-packages. We can
+         * safely remove all NULL elements from the PTYPE2 packages.
+         */
+        switch (package_type) {
+        case ACPI_PTYPE1_FIXED:
+        case ACPI_PTYPE1_VAR:
+        case ACPI_PTYPE1_OPTION:
+                return;
+
+        case ACPI_PTYPE2:
+        case ACPI_PTYPE2_COUNT:
+        case ACPI_PTYPE2_PKG_COUNT:
+        case ACPI_PTYPE2_FIXED:
+        case ACPI_PTYPE2_MIN:
+        case ACPI_PTYPE2_REV_FIXED:
+                break;
+
+        default:
+                return;
+        }
+
         count = obj_desc->package.count;
         new_count = count;
 
         source = obj_desc->package.elements;
         dest = source;
 
-        /* Examine all elements of the package object */
+        /* Examine all elements of the package object, remove nulls */
 
         for (i = 0; i < count; i++) {
                 if (!*source) {
-                        status = AE_NULL_ENTRY;
                         new_count--;
                 } else {
                         *dest = *source;
@@ -582,15 +592,18 @@ acpi_ns_remove_null_elements(union acpi_operand_object *obj_desc)
                 source++;
         }
 
-        if (status == AE_NULL_ENTRY) {
+        /* Update parent package if any null elements were removed */
+
+        if (new_count < count) {
+                ACPI_DEBUG_PRINT((ACPI_DB_REPAIR,
+                                  "%s: Found and removed %u NULL elements\n",
+                                  data->pathname, (count - new_count)));
 
                 /* NULL terminate list and update the package count */
 
                 *dest = NULL;
                 obj_desc->package.count = new_count;
         }
-
-        return (status);
 }
 
 /******************************************************************************