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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>
This commit is contained in:
Huang Shijie 2014-09-19 15:33:12 +08:00 committed by Greg Kroah-Hartman
parent bb2f861ad0
commit 45564a6656
1 changed files with 8 additions and 6 deletions
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14
drivers/tty/serial/imx.c
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@ -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);