1 files changed, 244 insertions, 97 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index cfcfd5ab06ce..99188c92068b 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -21,15 +21,18 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/tty.h>
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/uaccess.h>
+#include <linux/serial.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
 #include "pl2303.h"
@@ -136,21 +139,17 @@ static void destroy_serial(struct kref *kref)
 
 	dbg("%s - %s", __func__, serial->type->description);
 
-	serial->type->shutdown(serial);
-
 	/* return the minor range that this device had */
 	if (serial->minor != SERIAL_TTY_NO_MINOR)
 		return_serial(serial);
 
-	for (i = 0; i < serial->num_ports; ++i)
-		serial->port[i]->port.count = 0;
+	serial->type->release(serial);
 
-	/* the ports are cleaned up and released in port_release() */
-	for (i = 0; i < serial->num_ports; ++i)
-		if (serial->port[i]->dev.parent != NULL) {
-			device_unregister(&serial->port[i]->dev);
-			serial->port[i] = NULL;
-		}
+	for (i = 0; i < serial->num_ports; ++i) {
+		port = serial->port[i];
+		if (port)
+			put_device(&port->dev);
+	}
 
 	/* If this is a "fake" port, we have to clean it up here, as it will
 	 * not get cleaned up in port_release() as it was never registered with
@@ -159,9 +158,8 @@ static void destroy_serial(struct kref *kref)
 		for (i = serial->num_ports;
 					i < serial->num_port_pointers; ++i) {
 			port = serial->port[i];
-			if (!port)
-				continue;
-			port_free(port);
+			if (port)
+				port_free(port);
 		}
 	}
 
@@ -186,7 +184,8 @@ static int serial_open (struct tty_struct *tty, struct file *filp)
 	struct usb_serial *serial;
 	struct usb_serial_port *port;
 	unsigned int portNumber;
-	int retval;
+	int retval = 0;
+	int first = 0;
 
 	dbg("%s", __func__);
 
@@ -197,16 +196,24 @@ static int serial_open (struct tty_struct *tty, struct file *filp)
 		return -ENODEV;
 	}
 
+	mutex_lock(&serial->disc_mutex);
 	portNumber = tty->index - serial->minor;
 	port = serial->port[portNumber];
-	if (!port) {
+	if (!port || serial->disconnected)
 		retval = -ENODEV;
-		goto bailout_kref_put;
-	}
+	else
+		get_device(&port->dev);
+	/*
+	 * Note: Our locking order requirement does not allow port->mutex
+	 * to be acquired while serial->disc_mutex is held.
+	 */
+	mutex_unlock(&serial->disc_mutex);
+	if (retval)
+		goto bailout_serial_put;
 
 	if (mutex_lock_interruptible(&port->mutex)) {
 		retval = -ERESTARTSYS;
-		goto bailout_kref_put;
+		goto bailout_port_put;
 	}
 
 	++port->port.count;
@@ -216,8 +223,9 @@ static int serial_open (struct tty_struct *tty, struct file *filp)
 	tty->driver_data = port;
 	tty_port_tty_set(&port->port, tty);
 
-	if (port->port.count == 1) {
-
+	/* If the console is attached, the device is already open */
+	if (port->port.count == 1 && !port->console) {
+		first = 1;
 		/* lock this module before we call it
 		 * this may fail, which means we must bail out,
 		 * safe because we are called with BKL held */
@@ -226,33 +234,113 @@ static int serial_open (struct tty_struct *tty, struct file *filp)
 			goto bailout_mutex_unlock;
 		}
 
-		retval = usb_autopm_get_interface(serial->interface);
+		mutex_lock(&serial->disc_mutex);
+		if (serial->disconnected)
+			retval = -ENODEV;
+		else
+			retval = usb_autopm_get_interface(serial->interface);
 		if (retval)
 			goto bailout_module_put;
+
 		/* only call the device specific open if this
 		 * is the first time the port is opened */
 		retval = serial->type->open(tty, port, filp);
 		if (retval)
 			goto bailout_interface_put;
+		mutex_unlock(&serial->disc_mutex);
+		set_bit(ASYNCB_INITIALIZED, &port->port.flags);
 	}
-
 	mutex_unlock(&port->mutex);
-	return 0;
-
+	/* Now do the correct tty layer semantics */
+	retval = tty_port_block_til_ready(&port->port, tty, filp);
+	if (retval == 0) {
+		if (!first)
+			usb_serial_put(serial);
+		return 0;
+	}
+	mutex_lock(&port->mutex);
+	if (first == 0)
+		goto bailout_mutex_unlock;
+	/* Undo the initial port actions */
+	mutex_lock(&serial->disc_mutex);
 bailout_interface_put:
 	usb_autopm_put_interface(serial->interface);
 bailout_module_put:
+	mutex_unlock(&serial->disc_mutex);
 	module_put(serial->type->driver.owner);
 bailout_mutex_unlock:
 	port->port.count = 0;
 	tty->driver_data = NULL;
 	tty_port_tty_set(&port->port, NULL);
 	mutex_unlock(&port->mutex);
-bailout_kref_put:
+bailout_port_put:
+	put_device(&port->dev);
+bailout_serial_put:
 	usb_serial_put(serial);
 	return retval;
 }
 
+/**
+ *	serial_do_down		-	shut down hardware
+ *	@port: port to shut down
+ *
+ *	Shut down a USB port unless it is the console. We never shut down the
+ *	console hardware as it will always be in use.
+ *
+ *	Don't free any resources at this point
+ */
+static void serial_do_down(struct usb_serial_port *port)
+{
+	struct usb_serial_driver *drv = port->serial->type;
+	struct usb_serial *serial;
+	struct module *owner;
+
+	/* The console is magical, do not hang up the console hardware
+	   or there will be tears */
+	if (port->console)
+		return;
+
+	mutex_lock(&port->mutex);
+	serial = port->serial;
+	owner = serial->type->driver.owner;
+
+	if (drv->close)
+		drv->close(port);
+
+	mutex_unlock(&port->mutex);
+}
+
+/**
+ *	serial_do_free		-	free resources post close/hangup
+ *	@port: port to free up
+ *
+ *	Do the resource freeing and refcount dropping for the port. We must
+ *	be careful about ordering and we must avoid freeing up the console.
+ */
+
+static void serial_do_free(struct usb_serial_port *port)
+{
+	struct usb_serial *serial;
+	struct module *owner;
+
+	/* The console is magical, do not hang up the console hardware
+	   or there will be tears */
+	if (port->console)
+		return;
+
+	serial = port->serial;
+	owner = serial->type->driver.owner;
+	put_device(&port->dev);
+	/* Mustn't dereference port any more */
+	mutex_lock(&serial->disc_mutex);
+	if (!serial->disconnected)
+		usb_autopm_put_interface(serial->interface);
+	mutex_unlock(&serial->disc_mutex);
+	usb_serial_put(serial);
+	/* Mustn't dereference serial any more */
+	module_put(owner);
+}
+
 static void serial_close(struct tty_struct *tty, struct file *filp)
 {
 	struct usb_serial_port *port = tty->driver_data;
@@ -262,44 +350,39 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
 
 	dbg("%s - port %d", __func__, port->number);
 
-	mutex_lock(&port->mutex);
-
-	if (port->port.count == 0) {
-		mutex_unlock(&port->mutex);
+	/* FIXME:
+	   This leaves a very narrow race. Really we should do the
+	   serial_do_free() on tty->shutdown(), but tty->shutdown can
+	   be called from IRQ context and serial_do_free can sleep.
+
+	   The right fix is probably to make the tty free (which is rare)
+	   and thus tty->shutdown() occur via a work queue and simplify all
+	   the drivers that use it.
+	*/
+	if (tty_hung_up_p(filp)) {
+		/* serial_hangup already called serial_down at this point.
+		   Another user may have already reopened the port but
+		   serial_do_free is refcounted */
+		serial_do_free(port);
 		return;
 	}
 
-	if (port->port.count == 1)
-		/* only call the device specific close if this
-		 * port is being closed by the last owner. Ensure we do
-		 * this before we drop the port count. The call is protected
-		 * by the port mutex
-		 */
-		port->serial->type->close(tty, port, filp);
-
-	if (port->port.count == (port->console ? 2 : 1)) {
-		struct tty_struct *tty = tty_port_tty_get(&port->port);
-		if (tty) {
-			/* We must do this before we drop the port count to
-			   zero. */
-			if (tty->driver_data)
-				tty->driver_data = NULL;
-			tty_port_tty_set(&port->port, NULL);
-			tty_kref_put(tty);
-		}
-	}
+	if (tty_port_close_start(&port->port, tty, filp) == 0)
+		return;
 
-	if (port->port.count == 1) {
-		mutex_lock(&port->serial->disc_mutex);
-		if (!port->serial->disconnected)
-			usb_autopm_put_interface(port->serial->interface);
-		mutex_unlock(&port->serial->disc_mutex);
-		module_put(port->serial->type->driver.owner);
-	}
-	--port->port.count;
+	serial_do_down(port);		
+	tty_port_close_end(&port->port, tty);
+	tty_port_tty_set(&port->port, NULL);
+	serial_do_free(port);
+}
 
-	mutex_unlock(&port->mutex);
-	usb_serial_put(port->serial);
+static void serial_hangup(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	serial_do_down(port);
+	tty_port_hangup(&port->port);
+	/* We must not free port yet - the USB serial layer depends on it's
+	   continued existence */
 }
 
 static int serial_write(struct tty_struct *tty, const unsigned char *buf,
@@ -338,7 +421,6 @@ static int serial_chars_in_buffer(struct tty_struct *tty)
 	struct usb_serial_port *port = tty->driver_data;
 	dbg("%s = port %d", __func__, port->number);
 
-	WARN_ON(!port->port.count);
 	/* if the device was unplugged then any remaining characters
 	   fell out of the connector ;) */
 	if (port->serial->disconnected)
@@ -416,57 +498,52 @@ static int serial_break(struct tty_struct *tty, int break_state)
 	return 0;
 }
 
-static int serial_read_proc(char *page, char **start, off_t off, int count,
-							int *eof, void *data)
+static int serial_proc_show(struct seq_file *m, void *v)
 {
 	struct usb_serial *serial;
-	int length = 0;
 	int i;
-	off_t begin = 0;
 	char tmp[40];
 
 	dbg("%s", __func__);
-	length += sprintf(page, "usbserinfo:1.0 driver:2.0\n");
-	for (i = 0; i < SERIAL_TTY_MINORS && length < PAGE_SIZE; ++i) {
+	seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
+	for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
 		serial = usb_serial_get_by_index(i);
 		if (serial == NULL)
 			continue;
 
-		length += sprintf(page+length, "%d:", i);
+		seq_printf(m, "%d:", i);
 		if (serial->type->driver.owner)
-			length += sprintf(page+length, " module:%s",
+			seq_printf(m, " module:%s",
 				module_name(serial->type->driver.owner));
-		length += sprintf(page+length, " name:\"%s\"",
+		seq_printf(m, " name:\"%s\"",
 				serial->type->description);
-		length += sprintf(page+length, " vendor:%04x product:%04x",
+		seq_printf(m, " vendor:%04x product:%04x",
 			le16_to_cpu(serial->dev->descriptor.idVendor),
 			le16_to_cpu(serial->dev->descriptor.idProduct));
-		length += sprintf(page+length, " num_ports:%d",
-							serial->num_ports);
-		length += sprintf(page+length, " port:%d",
-							i - serial->minor + 1);
+		seq_printf(m, " num_ports:%d", serial->num_ports);
+		seq_printf(m, " port:%d", i - serial->minor + 1);
 		usb_make_path(serial->dev, tmp, sizeof(tmp));
-		length += sprintf(page+length, " path:%s", tmp);
+		seq_printf(m, " path:%s", tmp);
 
-		length += sprintf(page+length, "\n");
-		if ((length + begin) > (off + count)) {
-			usb_serial_put(serial);
-			goto done;
-		}
-		if ((length + begin) < off) {
-			begin += length;
-			length = 0;
-		}
+		seq_putc(m, '\n');
 		usb_serial_put(serial);
 	}
-	*eof = 1;
-done:
-	if (off >= (length + begin))
-		return 0;
-	*start = page + (off-begin);
-	return (count < begin+length-off) ? count : begin+length-off;
+	return 0;
 }
 
+static int serial_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, serial_proc_show, NULL);
+}
+
+static const struct file_operations serial_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= serial_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 static int serial_tiocmget(struct tty_struct *tty, struct file *file)
 {
 	struct usb_serial_port *port = tty->driver_data;
@@ -548,7 +625,13 @@ static void kill_traffic(struct usb_serial_port *port)
 
 static void port_free(struct usb_serial_port *port)
 {
+	/*
+	 * Stop all the traffic before cancelling the work, so that
+	 * nobody will restart it by calling usb_serial_port_softint.
+	 */
 	kill_traffic(port);
+	cancel_work_sync(&port->work);
+
 	usb_free_urb(port->read_urb);
 	usb_free_urb(port->write_urb);
 	usb_free_urb(port->interrupt_in_urb);
@@ -557,7 +640,6 @@ static void port_free(struct usb_serial_port *port)
 	kfree(port->bulk_out_buffer);
 	kfree(port->interrupt_in_buffer);
 	kfree(port->interrupt_out_buffer);
-	flush_scheduled_work();		/* port->work */
 	kfree(port);
 }
 
@@ -631,6 +713,29 @@ static struct usb_serial_driver *search_serial_device(
 	return NULL;
 }
 
+static int serial_carrier_raised(struct tty_port *port)
+{
+	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+	struct usb_serial_driver *drv = p->serial->type;
+	if (drv->carrier_raised)
+		return drv->carrier_raised(p);
+	/* No carrier control - don't block */
+	return 1;	
+}
+
+static void serial_dtr_rts(struct tty_port *port, int on)
+{
+	struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+	struct usb_serial_driver *drv = p->serial->type;
+	if (drv->dtr_rts)
+		drv->dtr_rts(p, on);
+}
+
+static const struct tty_port_operations serial_port_ops = {
+	.carrier_raised = serial_carrier_raised,
+	.dtr_rts = serial_dtr_rts,
+};
+
 int usb_serial_probe(struct usb_interface *interface,
 			       const struct usb_device_id *id)
 {
@@ -824,6 +929,7 @@ int usb_serial_probe(struct usb_interface *interface,
 		if (!port)
 			goto probe_error;
 		tty_port_init(&port->port);
+		port->port.ops = &serial_port_ops;
 		port->serial = serial;
 		spin_lock_init(&port->lock);
 		mutex_init(&port->mutex);
@@ -957,6 +1063,7 @@ int usb_serial_probe(struct usb_interface *interface,
 		if (retval > 0) {
 			/* quietly accept this device, but don't bind to a
 			   serial port as it's about to disappear */
+			serial->num_ports = 0;
 			goto exit;
 		}
 	}
@@ -977,10 +1084,15 @@ int usb_serial_probe(struct usb_interface *interface,
 
 		dev_set_name(&port->dev, "ttyUSB%d", port->number);
 		dbg ("%s - registering %s", __func__, dev_name(&port->dev));
+		port->dev_state = PORT_REGISTERING;
 		retval = device_register(&port->dev);
-		if (retval)
+		if (retval) {
 			dev_err(&port->dev, "Error registering port device, "
 				"continuing\n");
+			port->dev_state = PORT_UNREGISTERED;
+		} else {
+			port->dev_state = PORT_REGISTERED;
+		}
 	}
 
 	usb_serial_console_init(debug, minor);
@@ -1042,20 +1154,43 @@ void usb_serial_disconnect(struct usb_interface *interface)
 	usb_set_intfdata(interface, NULL);
 	/* must set a flag, to signal subdrivers */
 	serial->disconnected = 1;
+	mutex_unlock(&serial->disc_mutex);
+
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		if (port) {
 			struct tty_struct *tty = tty_port_tty_get(&port->port);
 			if (tty) {
+				/* The hangup will occur asynchronously but
+				   the object refcounts will sort out all the
+				   cleanup */
 				tty_hangup(tty);
 				tty_kref_put(tty);
 			}
 			kill_traffic(port);
+			cancel_work_sync(&port->work);
+			if (port->dev_state == PORT_REGISTERED) {
+
+				/* Make sure the port is bound so that the
+				 * driver's port_remove method is called.
+				 */
+				if (!port->dev.driver) {
+					int rc;
+
+					port->dev.driver =
+							&serial->type->driver;
+					rc = device_bind_driver(&port->dev);
+				}
+				port->dev_state = PORT_UNREGISTERING;
+				device_del(&port->dev);
+				port->dev_state = PORT_UNREGISTERED;
+			}
 		}
 	}
+	serial->type->disconnect(serial);
+
 	/* let the last holder of this object
 	 * cause it to be cleaned up */
-	mutex_unlock(&serial->disc_mutex);
 	usb_serial_put(serial);
 	dev_info(dev, "device disconnected\n");
 }
@@ -1067,6 +1202,8 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
 	struct usb_serial_port *port;
 	int i, r = 0;
 
+	serial->suspending = 1;
+
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		if (port)
@@ -1083,10 +1220,15 @@ EXPORT_SYMBOL(usb_serial_suspend);
 int usb_serial_resume(struct usb_interface *intf)
 {
 	struct usb_serial *serial = usb_get_intfdata(intf);
+	int rv;
 
+	serial->suspending = 0;
 	if (serial->type->resume)
-		return serial->type->resume(serial);
-	return 0;
+		rv = serial->type->resume(serial);
+	else
+		rv = usb_serial_generic_resume(serial);
+
+	return rv;
 }
 EXPORT_SYMBOL(usb_serial_resume);
 
@@ -1094,6 +1236,7 @@ static const struct tty_operations serial_ops = {
 	.open =			serial_open,
 	.close =		serial_close,
 	.write =		serial_write,
+	.hangup = 		serial_hangup,
 	.write_room =		serial_write_room,
 	.ioctl =		serial_ioctl,
 	.set_termios =		serial_set_termios,
@@ -1101,11 +1244,12 @@ static const struct tty_operations serial_ops = {
 	.unthrottle =		serial_unthrottle,
 	.break_ctl =		serial_break,
 	.chars_in_buffer =	serial_chars_in_buffer,
-	.read_proc =		serial_read_proc,
 	.tiocmget =		serial_tiocmget,
 	.tiocmset =		serial_tiocmset,
+	.proc_fops =		&serial_proc_fops,
 };
 
+
 struct tty_driver *usb_serial_tty_driver;
 
 static int __init usb_serial_init(void)
@@ -1221,8 +1365,8 @@ static void fixup_generic(struct usb_serial_driver *device)
 	set_to_generic_if_null(device, chars_in_buffer);
 	set_to_generic_if_null(device, read_bulk_callback);
 	set_to_generic_if_null(device, write_bulk_callback);
-	set_to_generic_if_null(device, shutdown);
-	set_to_generic_if_null(device, resume);
+	set_to_generic_if_null(device, disconnect);
+	set_to_generic_if_null(device, release);
 }
 
 int usb_serial_register(struct usb_serial_driver *driver)
@@ -1230,6 +1374,9 @@ int usb_serial_register(struct usb_serial_driver *driver)
 	/* must be called with BKL held */
 	int retval;
 
+	if (usb_disabled())
+		return -ENODEV;
+
 	fixup_generic(driver);
 
 	if (!driver->description)