USB: serial: sierra driver autopm fixes

This patch presents fixes for the autosuspend feature implementation in
sierra usb serial driver in  functions sierra_open(), sierra_close() and
stop_read_write_urbs().

The patch "sierra_close() must resume the device before it notifies it
of a closure" submitted by Oliver Neukum on Wed, October 14 has been
merged as fix in sierra_close() function.

The bug fix  in sierra_open() function restores the autopm interface
state on error condition.

The bug fix in in stop_read_write_urbs() function assures that both
receive and interrupt urbs are recycled.

Signed-off-by: Elina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/sierra.c

@@ -777,8 +777,11 @@ static void sierra_close(struct usb_serial_port *port)
 
 	if (serial->dev) {
 		mutex_lock(&serial->disc_mutex);
-		if (!serial->disconnected)
+		if (!serial->disconnected) {
+			serial->interface->needs_remote_wakeup = 0;
+			usb_autopm_get_interface(serial->interface);
 			sierra_send_setup(port);
+		}
 		mutex_unlock(&serial->disc_mutex);
 		spin_lock_irq(&intfdata->susp_lock);
 		portdata->opened = 0;
@@ -792,8 +795,6 @@ static void sierra_close(struct usb_serial_port *port)
 			sierra_release_urb(portdata->in_urbs[i]);
 			portdata->in_urbs[i] = NULL;
 		}
-		usb_autopm_get_interface(serial->interface);
-		serial->interface->needs_remote_wakeup = 0;
 	}
 }
 
@@ -831,6 +832,8 @@ static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port)
 	if (err) {
 		/* get rid of everything as in close */
 		sierra_close(port);
+		/* restore balance for autopm */
+		usb_autopm_put_interface(serial->interface);
 		return err;
 	}
 	sierra_send_setup(port);
@@ -919,16 +922,15 @@ static void sierra_release(struct usb_serial *serial)
 #ifdef CONFIG_PM
 static void stop_read_write_urbs(struct usb_serial *serial)
 {
-	int i, j;
+	int i;
 	struct usb_serial_port *port;
 	struct sierra_port_private *portdata;
 
 	/* Stop reading/writing urbs */
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		portdata = usb_get_serial_port_data(port);
-		for (j = 0; j < N_IN_URB; j++)
-			usb_kill_urb(portdata->in_urbs[j]);
+		sierra_stop_rx_urbs(port);
 		usb_kill_anchored_urbs(&portdata->active);
 	}
 }