serial: imx: terminate the RX DMA when the UART is suspending

When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.

Signed-off-by: Huang Shijie <b32955@freescale.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 c7683d747c18e12440c83ddd2fbead9e3d523a10..db749f768ac42bea092281b107e009d3d5e557f3 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -436,12 +436,14 @@ static void imx_stop_rx(struct uart_port *port)
        struct imx_port *sport = (struct imx_port *)port;
        unsigned long temp;
 
-       /*
-        * We are maybe in the SMP context, so if the DMA TX thread is running
-        * on other cpu, we have to wait for it to finish.
-        */
-       if (sport->dma_is_enabled && sport->dma_is_rxing)
-               return;
+       if (sport->dma_is_enabled && sport->dma_is_rxing) {
+               if (sport->port.suspended) {
+                       dmaengine_terminate_all(sport->dma_chan_rx);
+                       sport->dma_is_rxing = 0;
+               } else {
+                       return;
+               }
+       }
 
        temp = readl(sport->port.membase + UCR2);
        writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);