Update code for checking the reference count and performing the final

delete of objects.  Also revert our temporary workaround in dsmthdat.c
that always copied objects.  This is the correct fix for errors
evaluating _BST (and GBST) on IBM Thinkpads where an argument (Arg3)
was returned to the caller and the object was freed while still in use.
This will be in a future ACPI-CA dist.

Thanks to:	kochi@netbsd.org, shaohua.li@intel.com

1 files changed, 7 insertions, 23 deletions

diff --git a/sys/contrib/dev/acpica/dsmthdat.c b/sys/contrib/dev/acpica/dsmthdat.c
index ed3d14ef5118..3515957d2329 100644
--- a/sys/contrib/dev/acpica/dsmthdat.c
+++ b/sys/contrib/dev/acpica/dsmthdat.c
@@ -392,7 +392,6 @@ AcpiDsMethodDataSetValue (
 {
     ACPI_STATUS             Status;
     ACPI_NAMESPACE_NODE     *Node;
-    ACPI_OPERAND_OBJECT     *NewDesc = Object;
 
 
     ACPI_FUNCTION_TRACE ("DsMethodDataSetValue");
@@ -411,32 +410,17 @@ AcpiDsMethodDataSetValue (
         return_ACPI_STATUS (Status);
     }
 
-    /*
-     * If the object has just been created and is not attached to anything,
-     * (the reference count is 1), then we can just store it directly into
-     * the arg/local.  Otherwise, we must copy it.
+    /* 
+     * Increment ref count so object can't be deleted while installed.
+     * NOTE: We do not copy the object in order to preserve the call by
+     * reference semantics of ACPI Control Method invocation.
+     * (See ACPI Specification 2.0C)
      */
-    if (Object->Common.ReferenceCount > 1)
-    {
-        Status = AcpiUtCopyIobjectToIobject (Object, &NewDesc, WalkState);
-        if (ACPI_FAILURE (Status))
-        {
-            return_ACPI_STATUS (Status);
-        }
-
-       ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Object Copied %p, new %p\n",
-           Object, NewDesc));
-    }
-    else
-    {
-        /* Increment ref count so object can't be deleted while installed */
-
-        AcpiUtAddReference (NewDesc);
-    }
+    AcpiUtAddReference (Object);
 
     /* Install the object */
 
-    Node->Object = NewDesc;
+    Node->Object = Object;
     return_ACPI_STATUS (Status);
 }