* Added get_root() to device_manager_info. Surprisingly enough, it

returns the root device node. Now its actually possible to
  traverse the device node tree without a node to start with.
* Fixed execution order problem in dm_get_next_child_node(). The
  supplied node was put first (which could cause its immediate
  deletion), but was still accessed thereafter.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16268 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/drivers/device_manager.h

@@ -77,6 +77,7 @@ typedef struct device_manager_info {
 					device_node_handle *node);
 	status_t (*unregister_device)(device_node_handle node);
 
+	device_node_handle (*get_root)();
 	status_t (*get_next_child_device)(device_node_handle parent,
 		device_node_handle *_node, const device_attr *attrs);
 	device_node_handle (*get_parent)(device_node_handle node);
@@ -165,6 +166,7 @@ struct driver_module_info {
 #define B_MISC_DRIVER_TYPE			"misc"
 #define B_NETWORK_DRIVER_TYPE		"net"
 #define B_VIDEO_DRIVER_TYPE			"video"
+#define B_INTERRUPT_CONTROLLER_DRIVER_TYPE	"interrupt controller"
 
 #define PNP_DRIVER_CONNECTION "connection"
 	// connection of parent the device is attached to (optional, string)

src/system/kernel/device_manager/device_manager.c

@@ -79,6 +79,7 @@ device_manager_info gDeviceManagerModule = {
 	dm_register_node,
 	dm_unregister_node,
 
+	dm_get_root,
 	dm_get_next_child_node,
 	dm_get_parent,
 	dm_put_node,

src/system/kernel/device_manager/device_manager_private.h

@@ -173,6 +173,7 @@ status_t dm_init_nodes(void);
 void dm_put_node(device_node_info *node);
 status_t dm_get_next_child_node(device_node_info *parent,
 	device_node_info **_node, const device_attr *attrs);
+device_node_info *dm_get_root(void);
 device_node_info *dm_get_parent(device_node_info *node);
 
 

src/system/kernel/device_manager/nodes.c

@@ -328,7 +328,7 @@ dm_get_node(device_node_info *node)
 
 
 // remove node reference and clean it up if necessary
-// (node_lock must be hold)
+// (gNodeLock must be hold)
 
 void
 dm_put_node_nolock(device_node_info *node)
@@ -453,6 +453,14 @@ dm_put_node(device_node_info *node)
 }
 
 
+device_node_info *
+dm_get_root(void)
+{
+	dm_get_node(gRootNode);
+	return gRootNode;
+}
+
+
 device_node_info *
 dm_get_parent(device_node_info *node)
 {
@@ -466,9 +474,8 @@ dm_get_next_child_node(device_node_info *parent, device_node_info **_node,
 	const device_attr *attrs)
 {
 	device_node_info *node = *_node;
-	if (node != NULL)
-		dm_put_node(node);
-
+	device_node_info *nodeToPut = node;
+	
 	benaphore_lock(&gNodeLock);
 
 	while ((node = (device_node_info *)list_get_next_item(&parent->children, node)) != NULL) {
@@ -490,10 +497,18 @@ dm_get_next_child_node(device_node_info *parent, device_node_info **_node,
 		// we found a node
 		dm_get_node_nolock(node);
 		*_node = node;
+
+		if (nodeToPut != NULL)
+			dm_put_node_nolock(nodeToPut);
+
 		benaphore_unlock(&gNodeLock);
+		
 		return B_OK;
 	}
 
+	if (nodeToPut != NULL)
+		dm_put_node_nolock(nodeToPut);
+
 	benaphore_unlock(&gNodeLock);
 	return B_ENTRY_NOT_FOUND;
 }