usb serial core:

	- cleaned up some whitespace issues
	- changed MOD_INC logic for the generic driver
	- the port->sem lock is now taken by the serial core, not the individual
	  usb-serial drivers.  This is to reduce races.

drivers/usb/serial/usbserial.c

 /*
  * USB Serial Converter driver
  *
- * Copyright (C) 1999 - 2001 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
  * Copyright (c) 2000 Peter Berger (pberger@brimson.com)
  * Copyright (c) 2000 Al Borchers (borchers@steinerpoint.com)
  *
@@ -15,6 +15,13 @@
  *
  * See Documentation/usb/usb-serial.txt for more information on using this driver
  *
+ * (02/26/2002) gkh
+ *	Moved all locking into the main serial_* functions, instead of having 
+ *	the individual drivers have to grab the port semaphore.  This should
+ *	reduce races.
+ *	Reworked the MOD_INC logic a bit to always increment and decrement, even
+ *	if the generic driver is being used.
+ *
  * (10/10/2001) gkh
  *	usb_serial_disconnect() now sets the serial->dev pointer is to NULL to
  *	help prevent child drivers from accessing the device since it is now
@@ -337,6 +344,7 @@ static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
 
 /* All of the device info needed for the Generic Serial Converter */
 static struct usb_serial_device_type generic_device = {
+	owner:			THIS_MODULE,
 	name:			"Generic",
 	id_table:		generic_device_ids,
 	num_interrupt_in:	NUM_DONT_CARE,
@@ -345,13 +353,6 @@ static struct usb_serial_device_type generic_device = {
 	num_ports:		1,
 	shutdown:		generic_shutdown,
 };
-
-#define if_generic_do(x)			\
-	if ((serial->vendor == vendor) &&	\
-	    (serial->product == product))	\
-	                x
-#else
-#define if_generic_do(x)
 #endif
 
 
@@ -392,8 +393,6 @@ static struct tty_struct *	serial_tty[SERIAL_TTY_MINORS];
 static struct termios *		serial_termios[SERIAL_TTY_MINORS];
 static struct termios *		serial_termios_locked[SERIAL_TTY_MINORS];
 static struct usb_serial	*serial_table[SERIAL_TTY_MINORS];	/* initially all NULL */
-
-
 static LIST_HEAD(usb_serial_driver_list);
 
 
@@ -402,7 +401,6 @@ static struct usb_serial *get_serial_by_minor (unsigned int minor)
 	return serial_table[minor];
 }
 
-
 static struct usb_serial *get_free_serial (int num_ports, unsigned int *minor)
 {
 	struct usb_serial *serial = NULL;
@@ -439,7 +437,6 @@ static struct usb_serial *get_free_serial (int num_ports, unsigned int *minor)
 	return NULL;
 }
 
-
 static void return_serial (struct usb_serial *serial)
 {
 	int i;
@@ -456,7 +453,6 @@ static void return_serial (struct usb_serial *serial)
 	return;
 }
 
-
 #ifdef USES_EZUSB_FUNCTIONS
 /* EZ-USB Control and Status Register.  Bit 0 controls 8051 reset */
 #define CPUCS_REG    0x7F92
@@ -483,7 +479,6 @@ int ezusb_writememory (struct usb_serial *serial, int address, unsigned char *da
 	return result;
 }
 
-
 int ezusb_set_reset (struct usb_serial *serial, unsigned char reset_bit)
 {
 	int	response;
@@ -497,7 +492,6 @@ int ezusb_set_reset (struct usb_serial *serial, unsigned char reset_bit)
 
 #endif	/* USES_EZUSB_FUNCTIONS */
 
-
 /*****************************************************************************
  * Driver tty interface functions
  *****************************************************************************/
@@ -516,266 +510,293 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
 	/* get the serial object associated with this tty pointer */
 	serial = get_serial_by_minor (minor(tty->device));
 
-	if (serial_paranoia_check (serial, __FUNCTION__)) {
+	if (serial_paranoia_check (serial, __FUNCTION__))
 		return -ENODEV;
-	}
 
 	/* set up our port structure making the tty driver remember our port object, and us it */
 	portNumber = minor(tty->device) - serial->minor;
 	port = &serial->port[portNumber];
 	tty->driver_data = port;
+
+	down (&port->sem);
 	port->tty = tty;
 	 
-	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->open) {
+	/* lock this module before we call it */
 	if (serial->type->owner)
 		__MOD_INC_USE_COUNT(serial->type->owner);
+
+	/* pass on to the driver specific version of this function if it is available */
+	if (serial->type->open)
 		retval = serial->type->open(port, filp);
+	else
+		retval = generic_open(port, filp);
+
 	if (retval)
 		__MOD_DEC_USE_COUNT(serial->type->owner);
-	} else {
-		retval = generic_open(port, filp);
-	}
 
+	up (&port->sem);
 	return retval;
 }
 
-
 static void serial_close(struct tty_struct *tty, struct file * filp)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	if (!serial) {
+	if (!serial)
 		return;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
+	if (tty->driver_data == NULL) {
+		/* disconnect beat us to the punch here, so handle it gracefully */
+		goto exit;
+	}
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not opened");
-		return;
+		goto exit_no_mod_dec;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->close) {
+	if (serial->type->close)
 		serial->type->close(port, filp);
+	else
+		generic_close(port, filp);
+
+exit:
 	if (serial->type->owner)
 		__MOD_DEC_USE_COUNT(serial->type->owner);
-	} else {
-		generic_close(port, filp);
-	}
-}	
 
+exit_no_mod_dec:
+	up (&port->sem);
+}
 
 static int serial_write (struct tty_struct * tty, int from_user, const unsigned char *buf, int count)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
+	int retval = -EINVAL;
 
-	if (!serial) {
+	if (!serial)
 		return -ENODEV;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d, %d byte(s)", port->number, count);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not opened");
-		return -EINVAL;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->write) {
-		return (serial->type->write(port, from_user, buf, count));
-	} else {
-		return (generic_write(port, from_user, buf, count));
-	}
-}
+	if (serial->type->write)
+		retval = serial->type->write(port, from_user, buf, count);
+	else
+		retval = generic_write(port, from_user, buf, count);
 
+exit:
+	up (&port->sem);
+	return retval;
+}
 
 static int serial_write_room (struct tty_struct *tty) 
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
+	int retval = -EINVAL;
 
-	if (!serial) {
+	if (!serial)
 		return -ENODEV;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return -EINVAL;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->write_room) {
-		return (serial->type->write_room(port));
-	} else {
-		return (generic_write_room(port));
-	}
-}
+	if (serial->type->write_room)
+		retval = serial->type->write_room(port);
+	else
+		retval = generic_write_room(port);
 
+exit:
+	up (&port->sem);
+	return retval;
+}
 
 static int serial_chars_in_buffer (struct tty_struct *tty) 
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
+	int retval = -EINVAL;
 
-	if (!serial) {
+	if (!serial)
 		return -ENODEV;
-	}
+
+	down (&port->sem);
+
+	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return -EINVAL;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->chars_in_buffer) {
-		return (serial->type->chars_in_buffer(port));
-	} else {
-		return (generic_chars_in_buffer(port));
-	}
-}
+	if (serial->type->chars_in_buffer)
+		retval = serial->type->chars_in_buffer(port);
+	else
+		retval = generic_chars_in_buffer(port);
 
+exit:
+	up (&port->sem);
+	return retval;
+}
 
 static void serial_throttle (struct tty_struct * tty)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	if (!serial) {
+	if (!serial)
 		return;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function */
-	if (serial->type->throttle) {
+	if (serial->type->throttle)
 		serial->type->throttle(port);
-	}
 
-	return;
+exit:
+	up (&port->sem);
 }
 
-
 static void serial_unthrottle (struct tty_struct * tty)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	if (!serial) {
+	if (!serial)
 		return;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function */
-	if (serial->type->unthrottle) {
+	if (serial->type->unthrottle)
 		serial->type->unthrottle(port);
-	}
 
-	return;
+exit:
+	up (&port->sem);
 }
 
-
 static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
+	int retval = -ENODEV;
 
-	if (!serial) {
+	if (!serial)
 		return -ENODEV;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d, cmd 0x%.4x", port->number, cmd);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return -ENODEV;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->ioctl) {
-		return (serial->type->ioctl(port, file, cmd, arg));
-	} else {
-		return -ENOIOCTLCMD;
-	}
-}
+	if (serial->type->ioctl)
+		retval = serial->type->ioctl(port, file, cmd, arg);
+	else
+		retval = -ENOIOCTLCMD;
 
+exit:
+	up (&port->sem);
+	return retval;
+}
 
 static void serial_set_termios (struct tty_struct *tty, struct termios * old)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	if (!serial) {
+	if (!serial)
 		return;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return;
+		goto exit;
 	}
 
 	/* pass on to the driver specific version of this function if it is available */
-	if (serial->type->set_termios) {
+	if (serial->type->set_termios)
 		serial->type->set_termios(port, old);
-	}
 
-	return;
+exit:
+	up (&port->sem);
 }
 
-
 static void serial_break (struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;
 	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	if (!serial) {
+	if (!serial)
 		return;
-	}
+
+	down (&port->sem);
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
 	if (!port->open_count) {
 		dbg (__FUNCTION__ " - port not open");
-		return;
+		goto exit;
 	}
 
-	/* pass on to the driver specific version of this function if it is
-           available */
-	if (serial->type->break_ctl) {
+	/* pass on to the driver specific version of this function if it is available */
+	if (serial->type->break_ctl)
 		serial->type->break_ctl(port, break_state);
-	}
-}
 
+exit:
+	up (&port->sem);
+}
 
 static void serial_shutdown (struct usb_serial *serial)
 {
-	if (serial->type->shutdown) {
+	if (serial->type->shutdown)
 		serial->type->shutdown(serial);
-	} else {
+	else
 		generic_shutdown(serial);
-	}
 }
 
-
-
 /*****************************************************************************
  * generic devices specific driver functions
  *****************************************************************************/
@@ -787,13 +808,8 @@ static int generic_open (struct usb_serial_port *port, struct file *filp)
 	if (port_paranoia_check (port, __FUNCTION__))
 		return -ENODEV;
 
-	/* only increment our usage count, if this device is _really_ a generic device */
-	if_generic_do(MOD_INC_USE_COUNT);
-
 	dbg(__FUNCTION__ " - port %d", port->number);
 
-	down (&port->sem);
-	
 	++port->open_count;
 
 	if (port->open_count == 1) {
@@ -819,20 +835,15 @@ static int generic_open (struct usb_serial_port *port, struct file *filp)
 		}
 	}
 
-	up (&port->sem);
-	
 	return result;
 }
 
-
 static void generic_close (struct usb_serial_port *port, struct file * filp)
 {
 	struct usb_serial *serial = port->serial;
 
 	dbg(__FUNCTION__ " - port %d", port->number);
 
-	down (&port->sem);
-
 	--port->open_count;
 
 	if (port->open_count <= 0) {
@@ -845,14 +856,8 @@ static void generic_close (struct usb_serial_port *port, struct file * filp)
 		}
 		port->open_count = 0;
 	}
-
-	up (&port->sem);
-
-	/* only decrement our usage count, if this device is _really_ a generic device */
-	if_generic_do(MOD_DEC_USE_COUNT);
 }
 
-
 static int generic_write (struct usb_serial_port *port, int from_user, const unsigned char *buf, int count)
 {
 	struct usb_serial *serial = port->serial;
@@ -907,7 +912,6 @@ static int generic_write (struct usb_serial_port *port, int from_user, const uns
 	return (0);
 }
 
-
 static int generic_write_room (struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
@@ -924,7 +928,6 @@ static int generic_write_room (struct usb_serial_port *port)
 	return (room);
 }
 
-
 static int generic_chars_in_buffer (struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
@@ -941,7 +944,6 @@ static int generic_chars_in_buffer (struct usb_serial_port *port)
 	return (chars);
 }
 
-
 static void generic_read_bulk_callback (struct urb *urb)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
@@ -992,7 +994,6 @@ static void generic_read_bulk_callback (struct urb *urb)
 		err(__FUNCTION__ " - failed resubmitting read urb, error %d", result);
 }
 
-
 static void generic_write_bulk_callback (struct urb *urb)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
@@ -1016,7 +1017,6 @@ static void generic_write_bulk_callback (struct urb *urb)
 	return;
 }
 
-
 static void generic_shutdown (struct usb_serial *serial)
 {
 	int i;
@@ -1025,13 +1025,13 @@ static void generic_shutdown (struct usb_serial *serial)
 
 	/* stop reads and writes on all ports */
 	for (i=0; i < serial->num_ports; ++i) {
-		while (serial->port[i].open_count > 0) {
+		down (&serial->port[i].sem);
+		while (serial->port[i].open_count > 0)
 			generic_close (&serial->port[i], NULL);
-		}
+		up (&serial->port[i].sem);
 	}
 }
 
-
 static void port_softint(void *private)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *)private;
@@ -1053,8 +1053,6 @@ static void port_softint(void *private)
 	wake_up_interruptible(&tty->write_wait);
 }
 
-
-
 static void * usb_serial_probe(struct usb_device *dev, unsigned int ifnum,
 			       const struct usb_device_id *id)
 {
@@ -1080,7 +1078,6 @@ static void * usb_serial_probe(struct usb_device *dev, unsigned int ifnum,
 	int max_endpoints;
 	const struct usb_device_id *id_pattern = NULL;
 
-	
 	/* loop through our list of known serial converters, and see if this
 	   device matches. */
 	found = 0;
@@ -1331,7 +1328,6 @@ static void * usb_serial_probe(struct usb_device *dev, unsigned int ifnum,
 	return NULL;
 }
 
-
 static void usb_serial_disconnect(struct usb_device *dev, void *ptr)
 {
 	struct usb_serial *serial = (struct usb_serial *) ptr;
@@ -1341,8 +1337,10 @@ static void usb_serial_disconnect(struct usb_device *dev, void *ptr)
 	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;