[PATCH v3 2/6] serial: imx: only set dma_is_rxing when DMA starts

From: Martyn Welch
Date: Thu Sep 21 2017 - 12:18:32 EST


From: Romain Perier <romain.perier@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/imx.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index d90dae3..7835279 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -714,8 +714,6 @@ 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);
@@ -1074,6 +1072,7 @@ 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;
--
1.8.3.1