ACPICA: Add repair for predefined methods that return nested packages

Fixes a problem where a predefined method is defined to return
a variable-length Package of sub-packages. If the length is one,
the BIOS code occasionally creates a simple single package with
no sub-packages. This code attempts to fix the problem by wrapping
a new package object around the existing package. ACPICA BZ 790.

http://acpica.org/bugzilla/show_bug.cgi?id=790

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, 28 insertions, 2 deletions

diff --git a/drivers/acpi/acpica/nspredef.c b/drivers/acpi/acpica/nspredef.c
index e3f08dcb5275..0091504df074 100644
--- a/drivers/acpi/acpica/nspredef.c
+++ b/drivers/acpi/acpica/nspredef.c
@@ -566,9 +566,35 @@ acpi_ns_check_package(struct acpi_predefined_data *data,
         case ACPI_PTYPE2_COUNT:
 
                 /*
-                 * These types all return a single package that consists of a
-                 * variable number of sub-packages.
+                 * These types all return a single Package that consists of a
+                 * variable number of sub-Packages.
+                 *
+                 * First, ensure that the first element is a sub-Package. If not,
+                 * the BIOS may have incorrectly returned the object as a single
+                 * package instead of a Package of Packages (a common error if
+                 * there is only one entry). We may be able to repair this by
+                 * wrapping the returned Package with a new outer Package.
                  */
+                if ((*elements)->common.type != ACPI_TYPE_PACKAGE) {
+
+                        /* Create the new outer package and populate it */
+
+                        status =
+                            acpi_ns_repair_package_list(data,
+                                                        return_object_ptr);
+                        if (ACPI_FAILURE(status)) {
+                                return (status);
+                        }
+
+                        /* Update locals to point to the new package (of 1 element) */
+
+                        return_object = *return_object_ptr;
+                        elements = return_object->package.elements;
+                        count = 1;
+                }
+
+                /* Validate each sub-Package in the parent Package */
+
                 for (i = 0; i < count; i++) {
                         sub_package = *elements;
                         sub_elements = sub_package->package.elements;