ACPICA: Update comments

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 25 insertions, 21 deletions

diff --git a/drivers/acpi/namespace/nswalk.c b/drivers/acpi/namespace/nswalk.c
index a138fcb832a3..c6619d8a5164 100644
--- a/drivers/acpi/namespace/nswalk.c
+++ b/drivers/acpi/namespace/nswalk.c
@@ -193,21 +193,28 @@ acpi_ns_walk_namespace(acpi_object_type type,
                     acpi_ns_get_next_node(ACPI_TYPE_ANY, parent_node,
                                           child_node);
                 if (child_node) {
-                        /*
-                         * Found node, Get the type if we are not
-                         * searching for ANY
-                         */
+
+                        /* Found node, Get the type if we are not searching for ANY */
+
                         if (type != ACPI_TYPE_ANY) {
                                 child_type = child_node->type;
                         }
 
+                        /*
+                         * 1) Type must match
+                         * 2) Permanent namespace nodes are OK
+                         * 3) Ignore temporary nodes unless told otherwise. Typically,
+                         *    the temporary nodes can cause a race condition where they can
+                         *    be deleted during the execution of the user function. Only the
+                         *    debugger namespace dump will examine the temporary nodes.
+                         */
                         if ((child_type == type) &&
                             (!(child_node->flags & ANOBJ_TEMPORARY) ||
                              (child_node->flags & ANOBJ_TEMPORARY)
                              && (flags & ACPI_NS_WALK_TEMP_NODES))) {
                                 /*
-                                 * Found a matching node, invoke the user
-                                 * callback function
+                                 * Found a matching node, invoke the user callback function.
+                                 * Unlock the namespace if flag is set.
                                  */
                                 if (flags & ACPI_NS_WALK_UNLOCK) {
                                         mutex_status =
@@ -219,8 +226,9 @@ acpi_ns_walk_namespace(acpi_object_type type,
                                         }
                                 }
 
-                                status = user_function(child_node, level,
-                                                       context, return_value);
+                                status =
+                                    user_function(child_node, level, context,
+                                                  return_value);
 
                                 if (flags & ACPI_NS_WALK_UNLOCK) {
                                         mutex_status =
@@ -254,20 +262,17 @@ acpi_ns_walk_namespace(acpi_object_type type,
                         }
 
                         /*
-                         * Depth first search:
-                         * Attempt to go down another level in the namespace
-                         * if we are allowed to.  Don't go any further if we
-                         * have reached the caller specified maximum depth
-                         * or if the user function has specified that the
-                         * maximum depth has been reached.
+                         * Depth first search: Attempt to go down another level in the
+                         * namespace if we are allowed to.  Don't go any further if we have
+                         * reached the caller specified maximum depth or if the user
+                         * function has specified that the maximum depth has been reached.
                          */
                         if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
                                 if (acpi_ns_get_next_node
                                     (ACPI_TYPE_ANY, child_node, NULL)) {
-                                        /*
-                                         * There is at least one child of this
-                                         * node, visit the onde
-                                         */
+
+                                        /* There is at least one child of this node, visit it */
+
                                         level++;
                                         parent_node = child_node;
                                         child_node = NULL;
@@ -275,9 +280,8 @@ acpi_ns_walk_namespace(acpi_object_type type,
                         }
                 } else {
                         /*
-                         * No more children of this node (acpi_ns_get_next_node
-                         * failed), go back upwards in the namespace tree to
-                         * the node's parent.
+                         * No more children of this node (acpi_ns_get_next_node failed), go
+                         * back upwards in the namespace tree to the node's parent.
                          */
                         level--;
                         child_node = parent_node;