diff -Naru linux-4.9.87.orig/drivers/usb/class/cdc-acm.c linux-4.9.87/drivers/usb/class/cdc-acm.c
--- linux-4.9.87.orig/drivers/usb/class/cdc-acm.c	2019-01-21 09:33:23.938147201 -0600
+++ linux-4.9.87/drivers/usb/class/cdc-acm.c	2019-01-21 09:40:50.374133985 -0600
@@ -1161,8 +1161,10 @@
 	/* normal quirks */
 	quirks = (unsigned long)id->driver_info;
 
-	if (quirks == IGNORE_DEVICE)
+	if (quirks == IGNORE_DEVICE) {
+		dev_dbg(&intf->dev, "Ignoring device\n");
 		return -ENODEV;
+	}
 
 	memset(&h, 0x00, sizeof(struct usb_cdc_parsed_header));
 
@@ -1877,6 +1879,20 @@
 	.driver_info = IGNORE_DEVICE,
 	},
 
+	/* Ignore Exar XR21V141X usb serial chips
+	 * This elminates conflicting with the Exar vizzini driver.
+	 * The ACM driver cannot use features in the Exar chip,
+	 * such as setting the baud rate. */
+	{USB_DEVICE(0x04e2, 0x1410),
+	.driver_info = IGNORE_DEVICE,
+	},
+	{USB_DEVICE(0x04e2, 0x1412),
+	.driver_info = IGNORE_DEVICE,
+	},
+	{USB_DEVICE(0x04e2, 0x1414),
+	.driver_info = IGNORE_DEVICE,
+	},
+
 	/* control interfaces without any protocol set */
 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
 		USB_CDC_PROTO_NONE) },