serial: imx: change the wait even to interruptiable

The wait_event() makes the application hang for ever in the following case:
 [1] the hardware flow control is enabled.
 [2] the other end (or the remote end) is terminated, and the TX is still
     waiting for the hardware flow control signal to become asserted.

This patch fixes it by changing the wait_event to wait_event_interruptible.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index db749f768ac42bea092281b107e009d3d5e557f3..8f62a3cec23ef89d27217779f3cf9e378241f4b1 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1219,9 +1219,18 @@ static void imx_shutdown(struct uart_port *port)
        unsigned long flags;
 
        if (sport->dma_is_enabled) {
+               int ret;
+
                /* We have to wait for the DMA to finish. */
-               wait_event(sport->dma_wait,
+               ret = wait_event_interruptible(sport->dma_wait,
                        !sport->dma_is_rxing && !sport->dma_is_txing);
+               if (ret != 0) {
+                       sport->dma_is_rxing = 0;
+                       sport->dma_is_txing = 0;
+                       dmaengine_terminate_all(sport->dma_chan_tx);
+                       dmaengine_terminate_all(sport->dma_chan_rx);
+               }
+               imx_stop_tx(port);
                imx_stop_rx(port);
                imx_disable_dma(sport);
                imx_uart_dma_exit(sport);