Merge pull request #50 from MaxKrummenacher/4.14-2.0.x-imx

4.14 2.0.x imx

2 files changed, 71 insertions, 7 deletions

diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 972f5a5fe577..1f20fa0a67c0 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -560,9 +560,12 @@ static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 
 static void f81232_close(struct usb_serial_port *port)
 {
+	struct f81232_private *port_priv = usb_get_serial_port_data(port);
+
 	f81232_port_disable(port);
 	usb_serial_generic_close(port);
 	usb_kill_urb(port->interrupt_in_urb);
+	flush_work(&port_priv->interrupt_work);
 }
 
 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
@@ -656,6 +659,40 @@ static int f81232_port_remove(struct usb_serial_port *port)
 	return 0;
 }
 
+static int f81232_suspend(struct usb_serial *serial, pm_message_t message)
+{
+	struct usb_serial_port *port = serial->port[0];
+	struct f81232_private *port_priv = usb_get_serial_port_data(port);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
+		usb_kill_urb(port->read_urbs[i]);
+
+	usb_kill_urb(port->interrupt_in_urb);
+
+	if (port_priv)
+		flush_work(&port_priv->interrupt_work);
+
+	return 0;
+}
+
+static int f81232_resume(struct usb_serial *serial)
+{
+	struct usb_serial_port *port = serial->port[0];
+	int result;
+
+	if (tty_port_initialized(&port->port)) {
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
+		if (result) {
+			dev_err(&port->dev, "submit interrupt urb failed: %d\n",
+					result);
+			return result;
+		}
+	}
+
+	return usb_serial_generic_resume(serial);
+}
+
 static struct usb_serial_driver f81232_device = {
 	.driver = {
 		.owner =	THIS_MODULE,
@@ -679,6 +716,8 @@ static struct usb_serial_driver f81232_device = {
 	.read_int_callback =	f81232_read_int_callback,
 	.port_probe =		f81232_port_probe,
 	.port_remove =		f81232_port_remove,
+	.suspend =		f81232_suspend,
+	.resume =		f81232_resume,
 };
 
 static struct usb_serial_driver * const serial_drivers[] = {
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 35cb8c0e584f..efd7ce92878b 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -379,6 +379,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
 	struct usb_serial_port *port = urb->context;
 	unsigned char *data = urb->transfer_buffer;
 	unsigned long flags;
+	bool stopped = false;
 	int status = urb->status;
 	int i;
 
@@ -386,33 +387,51 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb)
 		if (urb == port->read_urbs[i])
 			break;
 	}
-	set_bit(i, &port->read_urbs_free);
 
 	dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
 							urb->actual_length);
 	switch (status) {
 	case 0:
+		usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
+							data);
+		port->serial->type->process_read_urb(urb);
 		break;
 	case -ENOENT:
 	case -ECONNRESET:
 	case -ESHUTDOWN:
 		dev_dbg(&port->dev, "%s - urb stopped: %d\n",
 							__func__, status);
-		return;
+		stopped = true;
+		break;
 	case -EPIPE:
 		dev_err(&port->dev, "%s - urb stopped: %d\n",
 							__func__, status);
-		return;
+		stopped = true;
+		break;
 	default:
 		dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
 							__func__, status);
-		goto resubmit;
+		break;
 	}
 
-	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
-	port->serial->type->process_read_urb(urb);
+	/*
+	 * Make sure URB processing is done before marking as free to avoid
+	 * racing with unthrottle() on another CPU. Matches the barriers
+	 * implied by the test_and_clear_bit() in
+	 * usb_serial_generic_submit_read_urb().
+	 */
+	smp_mb__before_atomic();
+	set_bit(i, &port->read_urbs_free);
+	/*
+	 * Make sure URB is marked as free before checking the throttled flag
+	 * to avoid racing with unthrottle() on another CPU. Matches the
+	 * smp_mb() in unthrottle().
+	 */
+	smp_mb__after_atomic();
+
+	if (stopped)
+		return;
 
-resubmit:
 	/* Throttle the device if requested by tty */
 	spin_lock_irqsave(&port->lock, flags);
 	port->throttled = port->throttle_req;
@@ -487,6 +506,12 @@ void usb_serial_generic_unthrottle(struct tty_struct *tty)
 	port->throttled = port->throttle_req = 0;
 	spin_unlock_irq(&port->lock);
 
+	/*
+	 * Matches the smp_mb__after_atomic() in
+	 * usb_serial_generic_read_bulk_callback().
+	 */
+	smp_mb();
+
 	if (was_throttled)
 		usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
 }