diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index b1e5db1..7175bb1 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -280,7 +280,10 @@
 		dbg("%s - Unable to send config request, "
 				"request=0x%x size=%d result=%d\n",
 				__func__, request, size, result);
-		return -EPROTO;
+		if (result > 0)
+			result = -EPROTO;
+
+		return result;
 	}
 
 	return 0;
@@ -331,7 +334,10 @@
 		dbg("%s - Unable to send request, "
 				"request=0x%x size=%d result=%d\n",
 				__func__, request, size, result);
-		return -EPROTO;
+		if (result > 0)
+			result = -EPROTO;
+
+		return result;
 	}
 
 	return 0;
@@ -395,10 +401,11 @@
 
 	dbg("%s - port %d", __func__, port->number);
 
-	if (cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_ENABLE)) {
-		dev_err(&port->dev, "%s - Unable to enable UART\n",
-				__func__);
-		return -EPROTO;
+	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
+								UART_ENABLE);
+	if (result) {
+		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
+		return result;
 	}
 
 	result = usb_serial_generic_open(tty, port);