ACPICA: Remove possibility of executing _REG methods twice

If a custom address space handler is installed by the host
before the "initialize operation regions" phase of the ACPICA
initialization, any _REG methods for that address space could
be executed twice. This change fixes the problem.
ACPICA BZ 427.

http://www.acpica.org/bugzilla/show_bug.cgi?id=427

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
index 98c7f9c626531f00e2bb9933c02ff61c8c0d42df..c9fa040725d4053f44e48b936dfbd570e9dc7f49 100644 (file)
--- a/drivers/acpi/acpica/evregion.c
+++ b/drivers/acpi/acpica/evregion.c
@@ -51,6 +51,10 @@
 ACPI_MODULE_NAME("evregion")
 
 /* Local prototypes */
+static u8
+acpi_ev_has_default_handler(struct acpi_namespace_node *node,
+                           acpi_adr_space_type space_id);
+
 static acpi_status
 acpi_ev_reg_run(acpi_handle obj_handle,
                u32 level, void *context, void **return_value);
@@ -140,6 +144,50 @@ acpi_status acpi_ev_install_region_handlers(void)
        return_ACPI_STATUS(status);
 }
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ev_has_default_handler
+ *
+ * PARAMETERS:  Node                - Namespace node for the device
+ *              space_id            - The address space ID
+ *
+ * RETURN:      TRUE if default handler is installed, FALSE otherwise
+ *
+ * DESCRIPTION: Check if the default handler is installed for the requested
+ *              space ID.
+ *
+ ******************************************************************************/
+
+static u8
+acpi_ev_has_default_handler(struct acpi_namespace_node *node,
+                           acpi_adr_space_type space_id)
+{
+       union acpi_operand_object *obj_desc;
+       union acpi_operand_object *handler_obj;
+
+       /* Must have an existing internal object */
+
+       obj_desc = acpi_ns_get_attached_object(node);
+       if (obj_desc) {
+               handler_obj = obj_desc->device.handler;
+
+               /* Walk the linked list of handlers for this object */
+
+               while (handler_obj) {
+                       if (handler_obj->address_space.space_id == space_id) {
+                               if (handler_obj->address_space.handler_flags &
+                                   ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
+                                       return (TRUE);
+                               }
+                       }
+
+                       handler_obj = handler_obj->address_space.next;
+               }
+       }
+
+       return (FALSE);
+}
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ev_initialize_op_regions
@@ -169,12 +217,18 @@ acpi_status acpi_ev_initialize_op_regions(void)
 
        for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
                /*
-                * TBD: Make sure handler is the DEFAULT handler, otherwise
-                * _REG will have already been run.
+                * Make sure the installed handler is the DEFAULT handler. If not the
+                * default, the _REG methods will have already been run (when the
+                * handler was installed)
                 */
-               status = acpi_ev_execute_reg_methods(acpi_gbl_root_node,
-                                                    acpi_gbl_default_address_spaces
-                                                    [i]);
+               if (acpi_ev_has_default_handler(acpi_gbl_root_node,
+                                               acpi_gbl_default_address_spaces
+                                               [i])) {
+                       status =
+                           acpi_ev_execute_reg_methods(acpi_gbl_root_node,
+                                                       acpi_gbl_default_address_spaces
+                                                       [i]);
+               }
        }
 
        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);