serial: tegra: fix tty-kref leak

Fix potential tty-kref leak in stop_rx path.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index d0d972f..0489a2b 100644 (file)
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -732,7 +732,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data)
 static void tegra_uart_stop_rx(struct uart_port *u)
 {
        struct tegra_uart_port *tup = to_tegra_uport(u);
-       struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+       struct tty_struct *tty;
        struct tty_port *port = &u->state->port;
        struct dma_tx_state state;
        unsigned long ier;
@@ -744,6 +744,8 @@ static void tegra_uart_stop_rx(struct uart_port *u)
        if (!tup->rx_in_progress)
                return;
 
+       tty = tty_port_tty_get(&tup->uport.state->port);
+
        tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
 
        ier = tup->ier_shadow;