USB: opticon: switch to generic read implementation

Switch to the more efficient generic read implementation.

Note that the generic implementation is not required to hold the tty
port mutex during resume due to the read-urb free mask and write start
flag.

Note also that the generic resume implementation will call generic
write start if there is a bulk-out end-point, but that nothing will be
submitted as the write fifo is not used and is empty.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/opticon.c

@@ -1,6 +1,7 @@
 /*
  * Opticon USB barcode to serial driver
  *
+ * Copyright (C) 2011 - 2012 Johan Hovold <jhovold@gmail.com>
  * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com>
  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
  * Copyright (C) 2008 - 2009 Novell Inc.
@@ -40,10 +41,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 
 /* This structure holds all of the individual device information */
 struct opticon_private {
-	struct urb *bulk_read_urb;
 	spinlock_t lock;	/* protects the following flags */
-	bool throttled;
-	bool actually_throttled;
 	bool rts;
 	bool cts;
 	int outstanding_urbs;
@@ -109,49 +107,6 @@ static void opticon_process_read_urb(struct urb *urb)
 	}
 }
 
-static void opticon_read_bulk_callback(struct urb *urb)
-{
-	struct usb_serial_port *port = urb->context;
-	struct opticon_private *priv = usb_get_serial_port_data(port);
-	unsigned char *data = urb->transfer_buffer;
-	int status = urb->status;
-	int result;
-
-	switch (status) {
-	case 0:
-		/* success */
-		break;
-	case -ECONNRESET:
-	case -ENOENT:
-	case -ESHUTDOWN:
-		/* this urb is terminated, clean up */
-		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
-			__func__, status);
-		return;
-	default:
-		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
-			__func__, status);
-		goto exit;
-	}
-
-	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
-
-	opticon_process_read_urb(urb);
-exit:
-	spin_lock(&priv->lock);
-
-	/* Continue trying to always read if we should */
-	if (!priv->throttled) {
-		result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
-		if (result)
-			dev_err(&port->dev,
-			    "%s - failed resubmitting read urb, error %d\n",
-							__func__, result);
-	} else
-		priv->actually_throttled = true;
-	spin_unlock(&priv->lock);
-}
-
 static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 				u8 val)
 {
@@ -179,11 +134,9 @@ static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	struct opticon_private *priv = usb_get_serial_port_data(port);
 	unsigned long flags;
-	int result = 0;
+	int res;
 
 	spin_lock_irqsave(&priv->lock, flags);
-	priv->throttled = false;
-	priv->actually_throttled = false;
 	priv->rts = false;
 	spin_unlock_irqrestore(&priv->lock, flags);
 
@@ -191,25 +144,17 @@ static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 	send_control_msg(port, CONTROL_RTS, 0);
 
 	/* clear the halt status of the enpoint */
-	usb_clear_halt(port->serial->dev, priv->bulk_read_urb->pipe);
+	usb_clear_halt(port->serial->dev, port->read_urb->pipe);
+
+	res = usb_serial_generic_open(tty, port);
+	if (!res)
+		return res;
 
-	result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
-	if (result)
-		dev_err(&port->dev,
-			"%s - failed resubmitting read urb, error %d\n",
-			__func__, result);
 	/* Request CTS line state, sometimes during opening the current
 	 * CTS state can be missed. */
 	send_control_msg(port, RESEND_CTS_STATE, 1);
-	return result;
-}
 
-static void opticon_close(struct usb_serial_port *port)
-{
-	struct opticon_private *priv = usb_get_serial_port_data(port);
-
-	/* shutdown our urbs */
-	usb_kill_urb(priv->bulk_read_urb);
+	return res;
 }
 
 static void opticon_write_control_callback(struct urb *urb)
@@ -346,40 +291,6 @@ static int opticon_write_room(struct tty_struct *tty)
 	return 2048;
 }
 
-static void opticon_throttle(struct tty_struct *tty)
-{
-	struct usb_serial_port *port = tty->driver_data;
-	struct opticon_private *priv = usb_get_serial_port_data(port);
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->lock, flags);
-	priv->throttled = true;
-	spin_unlock_irqrestore(&priv->lock, flags);
-}
-
-
-static void opticon_unthrottle(struct tty_struct *tty)
-{
-	struct usb_serial_port *port = tty->driver_data;
-	struct opticon_private *priv = usb_get_serial_port_data(port);
-	unsigned long flags;
-	int result, was_throttled;
-
-	spin_lock_irqsave(&priv->lock, flags);
-	priv->throttled = false;
-	was_throttled = priv->actually_throttled;
-	priv->actually_throttled = false;
-	spin_unlock_irqrestore(&priv->lock, flags);
-
-	if (was_throttled) {
-		result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
-		if (result)
-			dev_err(&port->dev,
-				"%s - failed submitting read urb, error %d\n",
-							__func__, result);
-	}
-}
-
 static int opticon_tiocmget(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
@@ -495,7 +406,6 @@ static int opticon_port_probe(struct usb_serial_port *port)
 		return -ENOMEM;
 
 	spin_lock_init(&priv->lock);
-	priv->bulk_read_urb = port->read_urbs[0];
 
 	usb_set_serial_port_data(port, priv);
 
@@ -511,32 +421,6 @@ static int opticon_port_remove(struct usb_serial_port *port)
 	return 0;
 }
 
-static int opticon_suspend(struct usb_serial *serial, pm_message_t message)
-{
-	struct opticon_private *priv;
-
-	priv = usb_get_serial_port_data(serial->port[0]);
-
-	usb_kill_urb(priv->bulk_read_urb);
-	return 0;
-}
-
-static int opticon_resume(struct usb_serial *serial)
-{
-	struct usb_serial_port *port = serial->port[0];
-	struct opticon_private *priv = usb_get_serial_port_data(port);
-	int result;
-
-	mutex_lock(&port->port.mutex);
-	/* This is protected by the port mutex against close/open */
-	if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
-		result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
-	else
-		result = 0;
-	mutex_unlock(&port->port.mutex);
-	return result;
-}
-
 static struct usb_serial_driver opticon_device = {
 	.driver = {
 		.owner =	THIS_MODULE,
@@ -549,17 +433,14 @@ static struct usb_serial_driver opticon_device = {
 	.port_probe =		opticon_port_probe,
 	.port_remove =		opticon_port_remove,
 	.open =			opticon_open,
-	.close =		opticon_close,
 	.write =		opticon_write,
 	.write_room = 		opticon_write_room,
-	.throttle = 		opticon_throttle,
-	.unthrottle =		opticon_unthrottle,
+	.throttle =		usb_serial_generic_throttle,
+	.unthrottle =		usb_serial_generic_unthrottle,
 	.ioctl =		opticon_ioctl,
 	.tiocmget =		opticon_tiocmget,
 	.tiocmset =		opticon_tiocmset,
-	.suspend = 		opticon_suspend,
-	.resume =		opticon_resume,
-	.read_bulk_callback =	opticon_read_bulk_callback,
+	.process_read_urb =	opticon_process_read_urb,
 };
 
 static struct usb_serial_driver * const serial_drivers[] = {