diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index f6ce321a86550e98c2d6ff0bb877c8fa09b328d8..41a45a5025b21275c818819ef77895468eba91fd 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -813,7 +813,9 @@ static void pl2303_update_line_status(struct usb_serial_port *port,
 	u8 length = UART_STATE;
 
 	if ((le16_to_cpu(port->serial->dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
-	    (le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X65)) {
+	    (le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X65 ||
+	     le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_SX1 ||
+	     le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X75)) {
 		length = 1;
 		status_idx = 0;
 	}