diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 6899aebfd6ae..dea039163661 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -392,12 +392,14 @@ static int digi_write_oob_command(struct usb_serial_port *port,
 			len &= ~3;
 		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
 		oob_port->write_urb->transfer_buffer_length = len;
+
 		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
-		if (ret == 0) {
-			oob_priv->dp_write_urb_in_use = 1;
-			count -= len;
-			buf += len;
-		}
+		if (ret)
+			break;
+
+		oob_priv->dp_write_urb_in_use = 1;
+		count -= len;
+		buf += len;
 	}
 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
 	if (ret)
@@ -427,20 +429,22 @@ static int digi_write_inb_command(struct usb_serial_port *port,
 	int len;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	unsigned char *data = port->write_urb->transfer_buffer;
+	unsigned long expire;
 	unsigned long flags;
 
 	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
 		priv->dp_port_num, count);
 
 	if (timeout)
-		timeout += jiffies;
-	else
-		timeout = ULONG_MAX;
+		expire = jiffies + timeout;
 
 	spin_lock_irqsave(&priv->dp_port_lock, flags);
 	while (count > 0 && ret == 0) {
-		while (priv->dp_write_urb_in_use &&
-		       time_before(jiffies, timeout)) {
+		while (priv->dp_write_urb_in_use) {
+			if (timeout && time_after(jiffies, expire)) {
+				ret = -ETIMEDOUT;
+				break;
+			}
 			cond_wait_interruptible_timeout_irqrestore(
 				&priv->write_wait, DIGI_RETRY_TIMEOUT,
 				&priv->dp_port_lock, flags);
@@ -449,6 +453,9 @@ static int digi_write_inb_command(struct usb_serial_port *port,
 			spin_lock_irqsave(&priv->dp_port_lock, flags);
 		}
 
+		if (ret)
+			break;
+
 		/* len must be a multiple of 4 and small enough to */
 		/* guarantee the write will send buffered data first, */
 		/* so commands are in order with data and not split */
@@ -1069,6 +1076,7 @@ static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
 	unsigned char buf[32];
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	struct ktermios not_termios;
+	int throttled;
 
 	/* be sure the device is started up */
 	if (digi_startup_device(port->serial) != 0)
@@ -1096,6 +1104,21 @@ static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
 		not_termios.c_iflag = ~tty->termios.c_iflag;
 		digi_set_termios(tty, port, &not_termios);
 	}
+
+	spin_lock_irq(&priv->dp_port_lock);
+	throttled = priv->dp_throttle_restart;
+	priv->dp_throttled = 0;
+	priv->dp_throttle_restart = 0;
+	spin_unlock_irq(&priv->dp_port_lock);
+
+	if (throttled) {
+		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
+		if (ret) {
+			dev_err(&port->dev, "failed to submit read urb: %d\n", ret);
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 3b99f9676c35..f05bcce60600 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -516,7 +516,7 @@ static int keyspan_pda_write_start(struct usb_serial_port *port)
 	if (count == room)
 		schedule_work(&priv->unthrottle_work);
 
-	return count;
+	return 0;
 }
 
 static void keyspan_pda_write_bulk_callback(struct urb *urb)
diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index 4c4009b8a46d..7275f4e7f569 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -1325,6 +1325,22 @@ static const struct usb_device_id option_ids[] = {
 	{ USB_DEVICE(TELIT_VENDOR_ID, TELIT_PRODUCT_CC864_SINGLE) },
 	{ USB_DEVICE(TELIT_VENDOR_ID, TELIT_PRODUCT_DE910_DUAL) },
 	{ USB_DEVICE(TELIT_VENDOR_ID, TELIT_PRODUCT_UE910_V2) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0990, 0xff, 0xff, 0x30),	/* Telit FE990D50 (RNDIS) */
+	  .driver_info = NCTRL(6) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0990, 0xff, 0xff, 0x40) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0990, 0xff, 0xff, 0x60) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0991, 0xff, 0xff, 0x30),	/* Telit FE990D50 (rmnet) */
+	  .driver_info = NCTRL(5) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0991, 0xff, 0xff, 0x40) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0991, 0xff, 0xff, 0x60) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0992, 0xff, 0xff, 0x30),	/* Telit FE990D50 (MBIM) */
+	  .driver_info = NCTRL(6) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0992, 0xff, 0xff, 0x40) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0992, 0xff, 0xff, 0x60) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0993, 0xff, 0xff, 0x30),	/* Telit FE990D50 (ECM) */
+	  .driver_info = NCTRL(6) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0993, 0xff, 0xff, 0x40) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(TELIT_VENDOR_ID, 0x0993, 0xff, 0xff, 0x60) },
 	{ USB_DEVICE_INTERFACE_CLASS(TELIT_VENDOR_ID, 0x1031, 0xff),	/* Telit LE910C1-EUX */
 	 .driver_info = NCTRL(0) | RSVD(3) },
 	{ USB_DEVICE_INTERFACE_CLASS(TELIT_VENDOR_ID, 0x1033, 0xff),	/* Telit LE910C1-EUX (ECM) */