1 files changed, 40 insertions, 18 deletions

diff --git a/sys/contrib/dev/acpica/dsutils.c b/sys/contrib/dev/acpica/dsutils.c
index e968e47..f20fb39 100644
--- a/sys/contrib/dev/acpica/dsutils.c
+++ b/sys/contrib/dev/acpica/dsutils.c
@@ -1,7 +1,7 @@
 /*******************************************************************************
  *
  * Module Name: dsutils - Dispatcher utilities
- *              $Revision: 102 $
+ *              $Revision: 107 $
  *
  ******************************************************************************/
 
@@ -134,11 +134,10 @@
  *
  * FUNCTION:    AcpiDsIsResultUsed
  *
- * PARAMETERS:  Op
- *              ResultObj
- *              WalkState
+ * PARAMETERS:  Op                  - Current Op
+ *              WalkState           - Current State
  *
- * RETURN:      Status
+ * RETURN:      TRUE if result is used, FALSE otherwise
  *
  * DESCRIPTION: Check if a result object will be used by the parent
  *
@@ -164,19 +163,41 @@ AcpiDsIsResultUsed (
     }
 
     /*
-     * If there is no parent, the result can't possibly be used!
-     * (An executing method typically has no parent, since each
-     * method is parsed separately)  However, a method that is
-     * invoked from another method has a parent.
+     * If there is no parent, we are executing at the method level.
+     * An executing method typically has no parent, since each method
+     * is parsed separately.
      */
     if (!Op->Common.Parent)
     {
+        /*
+         * If this is the last statement in the method, we know it is not a
+         * Return() operator (would not come here.) The following code is the
+         * optional support for a so-called "implicit return". Some AML code
+         * assumes that the last value of the method is "implicitly" returned
+         * to the caller. Just save the last result as the return value.
+         * NOTE: this is optional because the ASL language does not actually
+         * support this behavior.
+         */
+        if ((AcpiGbl_EnableInterpreterSlack) &&
+            (WalkState->ParserState.Aml >= WalkState->ParserState.AmlEnd))
+        {
+            ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
+                    "Result of [%s] will be implicitly returned\n",
+                    AcpiPsGetOpcodeName (Op->Common.AmlOpcode)));
+
+            /* Use the top of the result stack as the implicit return value */
+
+            WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc[0];
+            return_VALUE (TRUE);
+        }
+
+        /* No parent, the return value cannot possibly be used */
+
         return_VALUE (FALSE);
     }
 
-    /*
-     * Get info on the parent.  The root Op is AML_SCOPE
-     */
+    /* Get info on the parent. The RootOp is AML_SCOPE */
+
     ParentInfo = AcpiPsGetOpcodeInfo (Op->Common.Parent->Common.AmlOpcode);
     if (ParentInfo->Class == AML_CLASS_UNKNOWN)
     {
@@ -285,9 +306,9 @@ ResultNotUsed:
  *
  * FUNCTION:    AcpiDsDeleteResultIfNotUsed
  *
- * PARAMETERS:  Op
- *              ResultObj
- *              WalkState
+ * PARAMETERS:  Op              - Current parse Op
+ *              ResultObj       - Result of the operation
+ *              WalkState       - Current state
  *
  * RETURN:      Status
  *
@@ -400,7 +421,7 @@ AcpiDsClearOperands (
     UINT32                  i;
 
 
-    ACPI_FUNCTION_TRACE_PTR ("AcpiDsClearOperands", WalkState);
+    ACPI_FUNCTION_TRACE_PTR ("DsClearOperands", WalkState);
 
 
     /*
@@ -426,8 +447,9 @@ AcpiDsClearOperands (
  *
  * FUNCTION:    AcpiDsCreateOperand
  *
- * PARAMETERS:  WalkState
- *              Arg
+ * PARAMETERS:  WalkState       - Current walk state
+ *              Arg             - Parse object for the argument
+ *              ArgIndex        - Which argument (zero based)
  *
  * RETURN:      Status
  *