From 88cac66373365fa5ffc7d8ea4fd8a4f4152fa1d5 Mon Sep 17 00:00:00 2001
From: Nick Hibma <n_hibma@FreeBSD.org>
Date: Sun, 21 Feb 1999 16:53:35 +0000
Subject: [PATCH] Bug fix: Trap 12 when ugen not present and therefore
 unattached physical 	 device removed.

---
 sys/dev/usb/uhub.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sys/dev/usb/uhub.c b/sys/dev/usb/uhub.c
index 04c4054b073..5749f776609 100644
--- a/sys/dev/usb/uhub.c
+++ b/sys/dev/usb/uhub.c
@@ -456,9 +456,14 @@ uhub_disconnect_port(up)
 	struct softc {		/* all softc begin like this */
 		bdevice sc_dev;
 	};
+	struct softc *sc;
+	struct softc *scp;
 
-	struct softc *sc = (struct softc *)dev->softc;
-	struct softc *scp = (struct softc *)up->parent->softc;
+	if (!dev) 		/* no device driver attached at port */
+		return;
+
+	sc = (struct softc *)dev->softc;
+	scp = (struct softc *)up->parent->softc;
 
 	DPRINTFN(3,("uhub_disconnect_port: up=%p dev=%p port=%d\n", 
 		    up, dev, up->portno));