diff -Nru a/drivers/usb/serial/belkin_sa.c b/drivers/usb/serial/belkin_sa.c
--- a/drivers/usb/serial/belkin_sa.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/belkin_sa.c	Thu Mar 28 13:43:49 2002
@@ -361,8 +361,6 @@
 
 	dbg(__FUNCTION__" port %d", port->number);
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -375,7 +373,6 @@
 		port->active = 0;
 	}
 	
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 } /* belkin_sa_close */
 
diff -Nru a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c
--- a/drivers/usb/serial/cyberjack.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/cyberjack.c	Thu Mar 28 13:43:49 2002
@@ -193,8 +193,6 @@
 {
 	dbg(__FUNCTION__ " - port %d", port->number);
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -209,7 +207,6 @@
 		port->open_count = 0;
 	}
 
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 }
 
diff -Nru a/drivers/usb/serial/empeg.c b/drivers/usb/serial/empeg.c
--- a/drivers/usb/serial/empeg.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/empeg.c	Thu Mar 28 13:43:49 2002
@@ -212,8 +212,6 @@
 	if (!serial)
 		return;
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -224,8 +222,6 @@
 		port->active = 0;
 		port->open_count = 0;
 	}
-
-	up (&port->sem);
 
 	/* Uncomment the following line if you want to see some statistics in your syslog */
 	/* info ("Bytes In = %d  Bytes Out = %d", bytes_in, bytes_out); */
diff -Nru a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
--- a/drivers/usb/serial/ftdi_sio.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/ftdi_sio.c	Thu Mar 28 13:43:49 2002
@@ -380,7 +380,6 @@
 
 	dbg( __FUNCTION__);
 
-	down (&port->sem);
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -419,7 +418,6 @@
 		}
 	}
 
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 
 } /* ftdi_sio_close */
diff -Nru a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
--- a/drivers/usb/serial/ipaq.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/ipaq.c	Thu Mar 28 13:43:49 2002
@@ -224,8 +224,6 @@
 	if (!serial)
 		return;
 	
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -243,7 +241,6 @@
 		port->open_count = 0;
 
 	}
-	up (&port->sem);
 
 	/* Uncomment the following line if you want to see some statistics in your syslog */
 	/* info ("Bytes In = %d  Bytes Out = %d", bytes_in, bytes_out); */
diff -Nru a/drivers/usb/serial/ir-usb.c b/drivers/usb/serial/ir-usb.c
--- a/drivers/usb/serial/ir-usb.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/ir-usb.c	Thu Mar 28 13:43:49 2002
@@ -317,8 +317,6 @@
 	if (!serial)
 		return;
 	
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -330,7 +328,6 @@
 		port->open_count = 0;
 
 	}
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 }
 
diff -Nru a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
--- a/drivers/usb/serial/keyspan.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/keyspan.c	Thu Mar 28 13:43:49 2002
@@ -945,8 +945,6 @@
 	p_priv->out_flip = 0;
 	p_priv->in_flip = 0;
 
-	down (&port->sem);
-
 	if (--port->open_count <= 0) {
 		if (port->active) {
 			if (serial->dev) {
@@ -963,7 +961,6 @@
 		port->open_count = 0;
 		port->tty = 0;
 	}
-	up (&port->sem);
 
 	MOD_DEC_USE_COUNT;
 }
diff -Nru a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
--- a/drivers/usb/serial/keyspan_pda.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/keyspan_pda.c	Thu Mar 28 13:43:49 2002
@@ -738,8 +738,6 @@
 {
 	struct usb_serial *serial = port->serial;
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -756,7 +754,6 @@
 		port->open_count = 0;
 	}
 
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 }
 
diff -Nru a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
--- a/drivers/usb/serial/kl5kusb105.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/kl5kusb105.c	Thu Mar 28 13:43:49 2002
@@ -499,8 +499,6 @@
 	if(!serial)
 		return;
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -527,7 +525,6 @@
 		info("kl5kusb105 port stats: %ld bytes in, %ld bytes out", priv->bytes_in, priv->bytes_out);
 	}
 	
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 } /* klsi_105_close */
 
diff -Nru a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
--- a/drivers/usb/serial/mct_u232.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/mct_u232.c	Thu Mar 28 13:43:49 2002
@@ -479,8 +479,6 @@
 {
 	dbg(__FUNCTION__" port %d", port->number);
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -493,7 +491,6 @@
 		port->active = 0;
 	}
 	
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 } /* mct_u232_close */
 
diff -Nru a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
--- a/drivers/usb/serial/omninet.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/omninet.c	Thu Mar 28 13:43:49 2002
@@ -211,8 +211,6 @@
 	if (!serial)
 		return;
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -229,7 +227,6 @@
 			kfree(od);
 	}
 
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 }
 
diff -Nru a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
--- a/drivers/usb/serial/pl2303.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/pl2303.c	Thu Mar 28 13:43:49 2002
@@ -447,8 +447,6 @@
 	
 	dbg (__FUNCTION__ " - port %d", port->number);
 
-	down (&port->sem);
-
 	--port->open_count;
 	if (port->open_count <= 0) {
 		if (serial->dev) {
@@ -486,7 +484,6 @@
 		port->open_count = 0;
 	}
 
-	up (&port->sem);
 	MOD_DEC_USE_COUNT;
 }
 
diff -Nru a/drivers/usb/serial/usbserial.c b/drivers/usb/serial/usbserial.c
--- a/drivers/usb/serial/usbserial.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/usbserial.c	Thu Mar 28 13:43:49 2002
@@ -553,12 +553,21 @@
 		return;
 	}
 
+	down (&port->sem);
+
+	if (tty->driver_data == NULL) {
+		/* disconnect beat us to the punch here, so handle it gracefully */
+		goto exit;
+	}
+	
 	/* pass on to the driver specific version of this function if it is available */
 	if (serial->type->close) {
 		serial->type->close(port, filp);
 	} else {
 		generic_close(port, filp);
 	}
+exit:
+	up (&port->sem);
 }	
 
 
@@ -1350,8 +1359,10 @@
 	if (serial) {
 		/* fail all future close/read/write/ioctl/etc calls */
 		for (i = 0; i < serial->num_ports; ++i) {
+			down (&serial->port[i].sem);
 			if (serial->port[i].tty != NULL)
 				serial->port[i].tty->driver_data = NULL;
+			up (&serial->port[i].sem);
 		}
 
 		serial->dev = NULL;
diff -Nru a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
--- a/drivers/usb/serial/visor.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/visor.c	Thu Mar 28 13:43:49 2002
@@ -363,8 +363,6 @@
 	if (!serial)
 		return;
 	
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -389,7 +387,6 @@
 		port->active = 0;
 		port->open_count = 0;
 	}
-	up (&port->sem);
 
 	/* Uncomment the following line if you want to see some statistics in your syslog */
 	/* info ("Bytes In = %d  Bytes Out = %d", bytes_in, bytes_out); */
diff -Nru a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
--- a/drivers/usb/serial/whiteheat.c	Thu Mar 28 13:43:49 2002
+++ b/drivers/usb/serial/whiteheat.c	Thu Mar 28 13:43:49 2002
@@ -380,7 +380,6 @@
 	
 	dbg(__FUNCTION__ " - port %d", port->number);
 	
-	down (&port->sem);
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -398,7 +397,6 @@
 		port->active = 0;
 	}
 	MOD_DEC_USE_COUNT;
-	up (&port->sem);
 }