--- drivers/serial/21285.c	2009-12-18 17:27:07.000000000 -0500
+++ drivers/serial/21285.c	2009-12-28 16:30:02.000000000 -0500
@@ -63,6 +63,14 @@
 	}
 }
 
+static void serial21285_stop_tx_nosync(struct uart_port *port)
+{
+    if (tx_enabled(port)) {
+        disable_irq_nosync(IRQ_CONTX);
+        tx_enabled(port) = 0;
+    }
+}
+
 static void serial21285_start_tx(struct uart_port *port)
 {
 	if (!tx_enabled(port)) {
@@ -134,7 +142,7 @@
 		goto out;
 	}
 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
-		serial21285_stop_tx(port);
+		serial21285_stop_tx_nosync(port);
 		goto out;
 	}
 
@@ -150,7 +158,7 @@
 		uart_write_wakeup(port);
 
 	if (uart_circ_empty(xmit))
-		serial21285_stop_tx(port);
+		serial21285_stop_tx_nosync(port);
 
  out:
 	return IRQ_HANDLED;