diff --git a/drivers/tty/serial/pnx8xxx_uart.c b/drivers/tty/serial/pnx8xxx_uart.c
index b6b7aca..de6c05c 100644
--- a/drivers/tty/serial/pnx8xxx_uart.c
+++ b/drivers/tty/serial/pnx8xxx_uart.c
@@ -237,7 +237,10 @@
 		status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
 			 ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
 	}
+
+	spin_unlock(&sport->port.lock);
 	tty_flip_buffer_push(&sport->port.state->port);
+	spin_lock(&sport->port.lock);
 }
 
 static void pnx8xxx_tx_chars(struct pnx8xxx_port *sport)