diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 9489adbc4a2f..6d858bdaf33c 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -261,6 +261,7 @@ struct cp210x_serial_private {
 	speed_t			min_speed;
 	speed_t			max_speed;
 	bool			use_actual_rate;
+	bool			no_event_mode;
 };
 
 enum cp210x_event_state {
@@ -1332,12 +1333,16 @@ static void cp210x_change_speed(struct tty_struct *tty,
 
 static void cp210x_enable_event_mode(struct usb_serial_port *port)
 {
+	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
 	int ret;
 
 	if (port_priv->event_mode)
 		return;
 
+	if (priv->no_event_mode)
+		return;
+
 	port_priv->event_state = ES_DATA;
 	port_priv->event_mode = true;
 
@@ -2087,6 +2092,46 @@ static void cp210x_init_max_speed(struct usb_serial *serial)
 	priv->use_actual_rate = use_actual_rate;
 }
 
+static void cp2102_determine_quirks(struct usb_serial *serial)
+{
+	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
+	u8 *buf;
+	int ret;
+
+	buf = kmalloc(2, GFP_KERNEL);
+	if (!buf)
+		return;
+	/*
+	 * Some (possibly counterfeit) CP2102 do not support event-insertion
+	 * mode and respond differently to malformed vendor requests.
+	 * Specifically, they return one instead of two bytes when sent a
+	 * two-byte part-number request.
+	 */
+	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+			CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
+			CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
+	if (ret == 1) {
+		dev_dbg(&serial->interface->dev,
+				"device does not support event-insertion mode\n");
+		priv->no_event_mode = true;
+	}
+
+	kfree(buf);
+}
+
+static void cp210x_determine_quirks(struct usb_serial *serial)
+{
+	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
+
+	switch (priv->partnum) {
+	case CP210X_PARTNUM_CP2102:
+		cp2102_determine_quirks(serial);
+		break;
+	default:
+		break;
+	}
+}
+
 static int cp210x_attach(struct usb_serial *serial)
 {
 	int result;
@@ -2107,6 +2152,7 @@ static int cp210x_attach(struct usb_serial *serial)
 
 	usb_set_serial_data(serial, priv);
 
+	cp210x_determine_quirks(serial);
 	cp210x_init_max_speed(serial);
 
 	result = cp210x_gpio_init(serial);