1 files changed, 58 insertions, 38 deletions

diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
index 4929dbdbc8f0..ebef8a7fd707 100644
--- a/drivers/acpi/acpica/nsxfeval.c
+++ b/drivers/acpi/acpica/nsxfeval.c
@@ -6,7 +6,7 @@
  ******************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2008, Intel Corp.
+ * Copyright (C) 2000 - 2010, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -190,7 +190,7 @@ acpi_evaluate_object(acpi_handle handle,
 
         /* Convert and validate the device handle */
 
-        info->prefix_node = acpi_ns_map_handle_to_node(handle);
+        info->prefix_node = acpi_ns_validate_handle(handle);
         if (!info->prefix_node) {
                 status = AE_BAD_PARAMETER;
                 goto cleanup;
@@ -433,8 +433,11 @@ static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
  * PARAMETERS:  Type                - acpi_object_type to search for
  *              start_object        - Handle in namespace where search begins
  *              max_depth           - Depth to which search is to reach
- *              user_function       - Called when an object of "Type" is found
- *              Context             - Passed to user function
+ *              pre_order_visit     - Called during tree pre-order visit
+ *                                    when an object of "Type" is found
+ *              post_order_visit    - Called during tree post-order visit
+ *                                    when an object of "Type" is found
+ *              Context             - Passed to user function(s) above
  *              return_value        - Location where return value of
  *                                    user_function is put if terminated early
  *
@@ -443,16 +446,16 @@ static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
  *
  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
  *              starting (and ending) at the object specified by start_handle.
- *              The user_function is called whenever an object that matches
- *              the type parameter is found.  If the user function returns
+ *              The callback function is called whenever an object that matches
+ *              the type parameter is found. If the callback function returns
  *              a non-zero value, the search is terminated immediately and this
  *              value is returned to the caller.
  *
  *              The point of this procedure is to provide a generic namespace
  *              walk routine that can be called from multiple places to
- *              provide multiple services;  the User Function can be tailored
- *              to each task, whether it is a print function, a compare
- *              function, etc.
+ *              provide multiple services; the callback function(s) can be
+ *              tailored to each task, whether it is a print function,
+ *              a compare function, etc.
  *
  ******************************************************************************/
 
@@ -460,7 +463,8 @@ acpi_status
 acpi_walk_namespace(acpi_object_type type,
                     acpi_handle start_object,
                     u32 max_depth,
-                    acpi_walk_callback user_function,
+                    acpi_walk_callback pre_order_visit,
+                    acpi_walk_callback post_order_visit,
                     void *context, void **return_value)
 {
         acpi_status status;
@@ -469,7 +473,8 @@ acpi_walk_namespace(acpi_object_type type,
 
         /* Parameter validation */
 
-        if ((type > ACPI_TYPE_LOCAL_MAX) || (!max_depth) || (!user_function)) {
+        if ((type > ACPI_TYPE_LOCAL_MAX) ||
+            (!max_depth) || (!pre_order_visit && !post_order_visit)) {
                 return_ACPI_STATUS(AE_BAD_PARAMETER);
         }
 
@@ -501,8 +506,9 @@ acpi_walk_namespace(acpi_object_type type,
         }
 
         status = acpi_ns_walk_namespace(type, start_object, max_depth,
-                                        ACPI_NS_WALK_UNLOCK, user_function,
-                                        context, return_value);
+                                        ACPI_NS_WALK_UNLOCK, pre_order_visit,
+                                        post_order_visit, context,
+                                        return_value);
 
         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 
@@ -546,7 +552,7 @@ acpi_ns_get_device_callback(acpi_handle obj_handle,
                 return (status);
         }
 
-        node = acpi_ns_map_handle_to_node(obj_handle);
+        node = acpi_ns_validate_handle(obj_handle);
         status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
         if (ACPI_FAILURE(status)) {
                 return (status);
@@ -556,25 +562,20 @@ acpi_ns_get_device_callback(acpi_handle obj_handle,
                 return (AE_BAD_PARAMETER);
         }
 
-        /* Run _STA to determine if device is present */
-
-        status = acpi_ut_execute_STA(node, &flags);
-        if (ACPI_FAILURE(status)) {
-                return (AE_CTRL_DEPTH);
-        }
-
-        if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
-            !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
-                /*
-                 * Don't examine the children of the device only when the
-                 * device is neither present nor functional. See ACPI spec,
-                 * description of _STA for more information.
-                 */
-                return (AE_CTRL_DEPTH);
-        }
-
-        /* Filter based on device HID & CID */
-
+        /*
+         * First, filter based on the device HID and CID.
+         *
+         * 01/2010: For this case where a specific HID is requested, we don't
+         * want to run _STA until we have an actual HID match. Thus, we will
+         * not unnecessarily execute _STA on devices for which the caller
+         * doesn't care about. Previously, _STA was executed unconditionally
+         * on all devices found here.
+         *
+         * A side-effect of this change is that now we will continue to search
+         * for a matching HID even under device trees where the parent device
+         * would have returned a _STA that indicates it is not present or
+         * not functioning (thus aborting the search on that branch).
+         */
         if (info->hid != NULL) {
                 status = acpi_ut_execute_HID(node, &hid);
                 if (status == AE_NOT_FOUND) {
@@ -614,6 +615,25 @@ acpi_ns_get_device_callback(acpi_handle obj_handle,
                 }
         }
 
+        /* Run _STA to determine if device is present */
+
+        status = acpi_ut_execute_STA(node, &flags);
+        if (ACPI_FAILURE(status)) {
+                return (AE_CTRL_DEPTH);
+        }
+
+        if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
+            !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
+                /*
+                 * Don't examine the children of the device only when the
+                 * device is neither present nor functional. See ACPI spec,
+                 * description of _STA for more information.
+                 */
+                return (AE_CTRL_DEPTH);
+        }
+
+        /* We have a valid device, invoke the user function */
+
         status = info->user_function(obj_handle, nesting_level, info->context,
                                      return_value);
         return (status);
@@ -681,8 +701,8 @@ acpi_get_devices(const char *HID,
 
         status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
                                         ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
-                                        acpi_ns_get_device_callback, &info,
-                                        return_value);
+                                        acpi_ns_get_device_callback, NULL,
+                                        &info, return_value);
 
         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
         return_ACPI_STATUS(status);
@@ -723,7 +743,7 @@ acpi_attach_data(acpi_handle obj_handle,
 
         /* Convert and validate the handle */
 
-        node = acpi_ns_map_handle_to_node(obj_handle);
+        node = acpi_ns_validate_handle(obj_handle);
         if (!node) {
                 status = AE_BAD_PARAMETER;
                 goto unlock_and_exit;
@@ -769,7 +789,7 @@ acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
 
         /* Convert and validate the handle */
 
-        node = acpi_ns_map_handle_to_node(obj_handle);
+        node = acpi_ns_validate_handle(obj_handle);
         if (!node) {
                 status = AE_BAD_PARAMETER;
                 goto unlock_and_exit;
@@ -816,7 +836,7 @@ acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
 
         /* Convert and validate the handle */
 
-        node = acpi_ns_map_handle_to_node(obj_handle);
+        node = acpi_ns_validate_handle(obj_handle);
         if (!node) {
                 status = AE_BAD_PARAMETER;
                 goto unlock_and_exit;