Index: sys/sys/sysctl.h
===========================================================================
--- sys/sys/sysctl.h	2007/11/30 20:40:10	#55
+++ sys/sys/sysctl.h	2007/11/30 20:40:10
@@ -647,6 +647,7 @@
 		int kind, void *arg1, int arg2,
 		int (*handler) (SYSCTL_HANDLER_ARGS),
 		const char *fmt, const char *descr);
+void	sysctl_rename_oid(struct sysctl_oid *oidp, const char *name);
 int	sysctl_move_oid(struct sysctl_oid *oidp,
 		struct sysctl_oid_list *parent);
 int	sysctl_remove_oid(struct sysctl_oid *oidp, int del, int recurse);
Index: sys/kern/kern_sysctl.c
===========================================================================
--- sys/kern/kern_sysctl.c	2007/11/30 20:40:10	#68
+++ sys/kern/kern_sysctl.c	2007/11/30 20:40:10
@@ -415,6 +415,25 @@
 }
 
 /*
+ * Rename an existing oid.
+ */
+void
+sysctl_rename_oid(struct sysctl_oid *oidp, const char *name)
+{
+	ssize_t len;
+	char *newname;
+	void *oldname;
+
+	oldname = (void *)(uintptr_t)(const void *)oidp->oid_name;
+	len = strlen(name);
+	newname = malloc(len + 1, M_SYSCTLOID, M_WAITOK);
+	bcopy(name, newname, len + 1);
+	newname[len] = '\0';
+	oidp->oid_name = newname;
+	free(oldname, M_SYSCTLOID);
+}
+
+/*
  * Reparent an existing oid.
  */
 int
Index: sys/kern/subr_bus.c
===========================================================================
--- sys/kern/subr_bus.c	2007/11/30 20:40:10	#109
+++ sys/kern/subr_bus.c	2007/11/30 20:40:10
@@ -307,6 +307,16 @@
 }
 
 static void
+device_sysctl_update(device_t dev)
+{
+	devclass_t dc = dev->devclass;
+
+	if (dev->sysctl_tree == NULL)
+		return;
+	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
+}
+
+static void
 device_sysctl_fini(device_t dev)
 {
 	if (dev->sysctl_tree == NULL)
@@ -2387,6 +2397,7 @@
 		dev->state = DS_NOTPRESENT;
 		return (error);
 	}
+	device_sysctl_update(dev);
 	dev->state = DS_ATTACHED;
 	devadded(dev);
 	return (0);