serial: imx: only set dma_is_rxing when DMA starts

The variable dma_is_rxing is currently set to 1 in imx_disable_rx_int().
This is problematic as:

- whilst imx_disable_rx_int() is currently always called before
  start_rx_dma() this dependency isn't obvious.
- start_rx_dma() does error checking and might exit without
  enabling DMA. Currently this will result in dma_is_rxing suggesting
  that DMA is being used for recieving.

To avoid these issues, move the setting of dma_is_rxing to
start_rx_dma() when appropriate.

Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 20a8371..a42f386 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -716,8 +716,6 @@ static void imx_disable_rx_int(struct imx_port *sport)
 {
        unsigned long temp;
 
-       sport->dma_is_rxing = 1;
-
        /* disable the receiver ready and aging timer interrupts */
        temp = readl(sport->port.membase + UCR1);
        temp &= ~(UCR1_RRDYEN);
@@ -1076,6 +1074,7 @@ static int start_rx_dma(struct imx_port *sport)
        desc->callback_param = sport;
 
        dev_dbg(dev, "RX: prepare for the DMA.\n");
+       sport->dma_is_rxing = 1;
        sport->rx_cookie = dmaengine_submit(desc);
        dma_async_issue_pending(chan);
        return 0;