5 files changed, 103 insertions, 10 deletions

diff --git a/drivers/acpi/acpica/acutils.h b/drivers/acpi/acpica/acutils.h
index 5a6aa581e244..b0f5f92b674a 100644
--- a/drivers/acpi/acpica/acutils.h
+++ b/drivers/acpi/acpica/acutils.h
@@ -363,6 +363,10 @@ acpi_ut_execute_UID(struct acpi_namespace_node *device_node,
                     struct acpi_pnp_device_id ** return_id);
 
 acpi_status
+acpi_ut_execute_SUB(struct acpi_namespace_node *device_node,
+                    struct acpi_pnp_device_id **return_id);
+
+acpi_status
 acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
                     struct acpi_pnp_device_id_list ** return_cid_list);
 
diff --git a/drivers/acpi/acpica/nsxfname.c b/drivers/acpi/acpica/nsxfname.c
index 2d10df2ef660..811c6f13f476 100644
--- a/drivers/acpi/acpica/nsxfname.c
+++ b/drivers/acpi/acpica/nsxfname.c
@@ -231,6 +231,7 @@ static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
                                     struct acpi_pnp_device_id *source,
                                     char *string_area)
 {
+
         /* Create the destination PNP_DEVICE_ID */
 
         dest->string = string_area;
@@ -255,8 +256,8 @@ static char *acpi_ns_copy_device_id(struct acpi_pnp_device_id *dest,
  *              namespace node and possibly by running several standard
  *              control methods (Such as in the case of a device.)
  *
- * For Device and Processor objects, run the Device _HID, _UID, _CID, _STA,
- * _ADR, _sx_w, and _sx_d methods.
+ * For Device and Processor objects, run the Device _HID, _UID, _CID, _SUB,
+ * _STA, _ADR, _sx_w, and _sx_d methods.
  *
  * Note: Allocates the return buffer, must be freed by the caller.
  *
@@ -271,6 +272,7 @@ acpi_get_object_info(acpi_handle handle,
         struct acpi_pnp_device_id_list *cid_list = NULL;
         struct acpi_pnp_device_id *hid = NULL;
         struct acpi_pnp_device_id *uid = NULL;
+        struct acpi_pnp_device_id *sub = NULL;
         char *next_id_string;
         acpi_object_type type;
         acpi_name name;
@@ -315,7 +317,7 @@ acpi_get_object_info(acpi_handle handle,
         if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
                 /*
                  * Get extra info for ACPI Device/Processor objects only:
-                 * Run the Device _HID, _UID, and _CID methods.
+                 * Run the Device _HID, _UID, _SUB, and _CID methods.
                  *
                  * Note: none of these methods are required, so they may or may
                  * not be present for this device. The Info->Valid bitfield is used
@@ -338,6 +340,14 @@ acpi_get_object_info(acpi_handle handle,
                         valid |= ACPI_VALID_UID;
                 }
 
+                /* Execute the Device._SUB method */
+
+                status = acpi_ut_execute_SUB(node, &sub);
+                if (ACPI_SUCCESS(status)) {
+                        info_size += sub->length;
+                        valid |= ACPI_VALID_SUB;
+                }
+
                 /* Execute the Device._CID method */
 
                 status = acpi_ut_execute_CID(node, &cid_list);
@@ -425,8 +435,9 @@ acpi_get_object_info(acpi_handle handle,
         }
 
         /*
-         * Copy the HID, UID, and CIDs to the return buffer. The variable-length
-         * strings are copied to the reserved area at the end of the buffer.
+         * Copy the HID, UID, SUB, and CIDs to the return buffer.
+         * The variable-length strings are copied to the reserved area
+         * at the end of the buffer.
          *
          * For HID and CID, check if the ID is a PCI Root Bridge.
          */
@@ -444,6 +455,11 @@ acpi_get_object_info(acpi_handle handle,
                                                         uid, next_id_string);
         }
 
+        if (sub) {
+                next_id_string = acpi_ns_copy_device_id(&info->subsystem_id,
+                                                        sub, next_id_string);
+        }
+
         if (cid_list) {
                 info->compatible_id_list.count = cid_list->count;
                 info->compatible_id_list.list_size = cid_list->list_size;
@@ -480,6 +496,9 @@ acpi_get_object_info(acpi_handle handle,
         if (uid) {
                 ACPI_FREE(uid);
         }
+        if (sub) {
+                ACPI_FREE(sub);
+        }
         if (cid_list) {
                 ACPI_FREE(cid_list);
         }
diff --git a/drivers/acpi/acpica/utids.c b/drivers/acpi/acpica/utids.c
index f18ac81c8399..774c3aefbf5d 100644
--- a/drivers/acpi/acpica/utids.c
+++ b/drivers/acpi/acpica/utids.c
@@ -127,6 +127,73 @@ cleanup:
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_ut_execute_SUB
+ *
+ * PARAMETERS:  device_node         - Node for the device
+ *              return_id           - Where the _SUB is returned
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Executes the _SUB control method that returns the subsystem
+ *              ID of the device. The _SUB value is always a string containing
+ *              either a valid PNP or ACPI ID.
+ *
+ *              NOTE: Internal function, no parameter validation
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ut_execute_SUB(struct acpi_namespace_node *device_node,
+                    struct acpi_pnp_device_id **return_id)
+{
+        union acpi_operand_object *obj_desc;
+        struct acpi_pnp_device_id *sub;
+        u32 length;
+        acpi_status status;
+
+        ACPI_FUNCTION_TRACE(ut_execute_SUB);
+
+        status = acpi_ut_evaluate_object(device_node, METHOD_NAME__SUB,
+                                         ACPI_BTYPE_STRING, &obj_desc);
+        if (ACPI_FAILURE(status)) {
+                return_ACPI_STATUS(status);
+        }
+
+        /* Get the size of the String to be returned, includes null terminator */
+
+        length = obj_desc->string.length + 1;
+
+        /* Allocate a buffer for the SUB */
+
+        sub =
+            ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
+                                 (acpi_size) length);
+        if (!sub) {
+                status = AE_NO_MEMORY;
+                goto cleanup;
+        }
+
+        /* Area for the string starts after PNP_DEVICE_ID struct */
+
+        sub->string =
+            ACPI_ADD_PTR(char, sub, sizeof(struct acpi_pnp_device_id));
+
+        /* Simply copy existing string */
+
+        ACPI_STRCPY(sub->string, obj_desc->string.pointer);
+        sub->length = length;
+        *return_id = sub;
+
+      cleanup:
+
+        /* On exit, we must delete the return object */
+
+        acpi_ut_remove_reference(obj_desc);