1 files changed, 18 insertions, 4 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 6bc20d7..65db939 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -91,6 +91,9 @@ static void __uart_start(struct tty_struct *tty)
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
 
+	if (port->ops->wake_peer)
+		port->ops->wake_peer(port);
+
 	if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
 	    !tty->stopped && !tty->hw_stopped)
 		port->ops->start_tx(port);
@@ -159,13 +162,17 @@ static int uart_startup(struct tty_struct *tty, struct uart_state *state, int in
 	 * buffer.
 	 */
 	if (!state->xmit.buf) {
+		unsigned long flags;
+
 		/* This is protected by the per port mutex */
 		page = get_zeroed_page(GFP_KERNEL);
 		if (!page)
 			return -ENOMEM;
 
+		spin_lock_irqsave(&uport->lock, flags);
 		state->xmit.buf = (unsigned char *) page;
 		uart_circ_clear(&state->xmit);
+		spin_unlock_irqrestore(&uport->lock, flags);
 	}
 
 	retval = uport->ops->startup(uport);
@@ -258,8 +265,11 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 	 * Free the transmit buffer page.
 	 */
 	if (state->xmit.buf) {
+		unsigned long flags;
+		spin_lock_irqsave(&uport->lock, flags);
 		free_page((unsigned long)state->xmit.buf);
 		state->xmit.buf = NULL;
+		spin_unlock_irqrestore(&uport->lock, flags);
 	}
 }
 
@@ -468,10 +478,12 @@ static inline int __uart_put_char(struct uart_port *port,
 	unsigned long flags;
 	int ret = 0;
 
-	if (!circ->buf)
+	spin_lock_irqsave(&port->lock, flags);
+	if (!circ->buf) {
+		spin_unlock_irqrestore(&port->lock, flags);
 		return 0;
+	}
 
-	spin_lock_irqsave(&port->lock, flags);
 	if (uart_circ_chars_free(circ) != 0) {
 		circ->buf[circ->head] = c;
 		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
@@ -514,10 +526,12 @@ static int uart_write(struct tty_struct *tty,
 	port = state->uart_port;
 	circ = &state->xmit;
 
-	if (!circ->buf)
+	spin_lock_irqsave(&port->lock, flags);
+	if (!circ->buf) {
+		spin_unlock_irqrestore(&port->lock, flags);
 		return 0;
+	}
 
-	spin_lock_irqsave(&port->lock, flags);
 	while (1) {
 		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 		if (count < c)