diff --git a/source/compiler/aslmessages.h b/source/compiler/aslmessages.h
index bf8b67eb5..0d38ab37c 100644
--- a/source/compiler/aslmessages.h
+++ b/source/compiler/aslmessages.h
@@ -145,6 +145,8 @@ typedef enum
     ASL_MSG_CLOSE,
     ASL_MSG_COMPILER_INTERNAL,
     ASL_MSG_COMPILER_RESERVED,
+    ASL_MSG_CONNECTION_MISSING,
+    ASL_MSG_CONNECTION_INVALID,
     ASL_MSG_CONSTANT_EVALUATION,
     ASL_MSG_CONSTANT_FOLDED,
     ASL_MSG_CORE_EXCEPTION,
@@ -165,6 +167,8 @@ typedef enum
     ASL_MSG_FIELD_UNIT_OFFSET,
     ASL_MSG_GPE_NAME_CONFLICT,
     ASL_MSG_HID_LENGTH,
+    ASL_MSG_HID_PREFIX,
+    ASL_MSG_HID_SUFFIX,
     ASL_MSG_INCLUDE_FILE_OPEN,
     ASL_MSG_INPUT_FILE_OPEN,
     ASL_MSG_INTEGER_LENGTH,
@@ -301,6 +305,8 @@ char                        *AslMessages [] = {
 /*    ASL_MSG_CLOSE */                      "Could not close file",
 /*    ASL_MSG_COMPILER_INTERNAL */          "Internal compiler error",
 /*    ASL_MSG_COMPILER_RESERVED */          "Use of compiler reserved name",
+/*    ASL_MSG_CONNECTION_MISSING */         "A Connection operator is required for this field SpaceId",
+/*    ASL_MSG_CONNECTION_INVALID */         "Invalid OpRegion SpaceId for use of Connection operator",
 /*    ASL_MSG_CONSTANT_EVALUATION */        "Could not evaluate constant expression",
 /*    ASL_MSG_CONSTANT_FOLDED */            "Constant expression evaluated and reduced",
 /*    ASL_MSG_CORE_EXCEPTION */             "From ACPI CA Subsystem",
@@ -321,6 +327,8 @@ char                        *AslMessages [] = {
 /*    ASL_MSG_FIELD_UNIT_OFFSET */          "Field Unit extends beyond region limit",
 /*    ASL_MSG_GPE_NAME_CONFLICT */          "Name conflicts with a previous GPE method",
 /*    ASL_MSG_HID_LENGTH */                 "_HID string must be exactly 7 or 8 characters",
+/*    ASL_MSG_HID_PREFIX */                 "_HID prefix must be all uppercase or decimal digits",
+/*    ASL_MSG_HID_SUFFIX */                 "_HID suffix must be all hex digits",
 /*    ASL_MSG_INCLUDE_FILE_OPEN */          "Could not open include file",
 /*    ASL_MSG_INPUT_FILE_OPEN */            "Could not open input file",
 /*    ASL_MSG_INTEGER_LENGTH */             "64-bit integer in 32-bit table, truncating",
diff --git a/source/compiler/aslwalks.c b/source/compiler/aslwalks.c
index ae1716ade..7b178baee 100644
--- a/source/compiler/aslwalks.c
+++ b/source/compiler/aslwalks.c
@@ -1104,6 +1104,7 @@ AnOtherSemanticAnalysisWalkBegin (
     ACPI_PARSE_OBJECT       *ArgNode;
     ACPI_PARSE_OBJECT       *PrevArgNode = NULL;
     const ACPI_OPCODE_INFO  *OpInfo;
+    ACPI_NAMESPACE_NODE     *Node;
 
 
     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
@@ -1228,6 +1229,74 @@ AnOtherSemanticAnalysisWalkBegin (
         }
         break;
 
+    case PARSEOP_CONNECTION:
+        /*
+         * Ensure that the referenced operation region has the correct SPACE_ID.
+         * From the grammar/parser, we know the parent is a FIELD definition.
+         */
+        ArgNode = Op->Asl.Parent;       /* Field definition */
+        ArgNode = ArgNode->Asl.Child;   /* First child is the OpRegion Name */
+        Node = ArgNode->Asl.Node;       /* OpRegion namespace node */
+
+        ArgNode = Node->Op;             /* OpRegion definition */
+        ArgNode = ArgNode->Asl.Child;   /* First child is the OpRegion Name */
+        ArgNode = ArgNode->Asl.Next;    /* Next peer is the SPACE_ID (what we want) */
+
+        /*
+         * The Connection() operator is only valid for the following operation
+         * region SpaceIds: GeneralPurposeIo and GenericSerialBus.
+         */
+        if ((ArgNode->Asl.Value.Integer != ACPI_ADR_SPACE_GPIO) &&
+            (ArgNode->Asl.Value.Integer != ACPI_ADR_SPACE_GSBUS))
+        {
+            AslError (ASL_ERROR, ASL_MSG_CONNECTION_INVALID, Op, NULL);
+        }
+        break;
+
+    case PARSEOP_FIELD:
+        /*
+         * Ensure that fields for GeneralPurposeIo and GenericSerialBus
+         * contain at least one Connection() operator
+         */
+        ArgNode = Op->Asl.Child;        /* 1st child is the OpRegion Name */
+        Node = ArgNode->Asl.Node;       /* OpRegion namespace node */
+
+        ArgNode = Node->Op;             /* OpRegion definition */
+        ArgNode = ArgNode->Asl.Child;   /* First child is the OpRegion Name */
+        ArgNode = ArgNode->Asl.Next;    /* Next peer is the SPACE_ID (what we want) */
+
+        /* We are only interested in GeneralPurposeIo and GenericSerialBus */
+
+        if ((ArgNode->Asl.Value.Integer != ACPI_ADR_SPACE_GPIO) &&
+            (ArgNode->Asl.Value.Integer != ACPI_ADR_SPACE_GSBUS))
+        {
+            break;
+        }
+
+        ArgNode = Op->Asl.Child;        /* 1st child is the OpRegion Name */
+        ArgNode = ArgNode->Asl.Next;    /* AccessType */
+        ArgNode = ArgNode->Asl.Next;    /* LockRule */
+        ArgNode = ArgNode->Asl.Next;    /* UpdateRule */
+        ArgNode = ArgNode->Asl.Next;    /* Start of FieldUnitList */
+
+        /* Walk the FieldUnitList */
+
+        while (ArgNode)
+        {
+            if (ArgNode->Asl.ParseOpcode == PARSEOP_CONNECTION)
+            {
+                break;
+            }
+            else if (ArgNode->Asl.ParseOpcode == PARSEOP_NAMESEG)
+            {
+                AslError (ASL_ERROR, ASL_MSG_CONNECTION_MISSING, ArgNode, NULL);
+                break;
+            }
+
+            ArgNode = ArgNode->Asl.Next;
+        }
+        break;
+
     default:
         break;
     }