serial: 8250: add serial transmitter fully empty test

[net-next-2.6.git] / drivers / serial / 8250.c

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c3e37c8e7e26a8b8ecc4a767561aea15b2378909..e9b15c3746fa0307bc91c929c929374efd0f1bea 100644 (file)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -83,6 +83,9 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */
 
 #define PASS_LIMIT     256
 
+#define BOTH_EMPTY     (UART_LSR_TEMT | UART_LSR_THRE)
+
+
 /*
  * We default to IRQ0 for the "no irq" hack.   Some
  * machine types want others as well - they're free
@@ -1792,7 +1795,7 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
        up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
        spin_unlock_irqrestore(&up->port.lock, flags);
 
-       return lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+       return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
 }
 
 static unsigned int serial8250_get_mctrl(struct uart_port *port)
@@ -1850,8 +1853,6 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
        spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
-#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
-
 /*
  *     Wait for transmitter & holding register to empty
  */