serial: imx: initialized DMA w/o HW flow enabled

DMA mode for UART can be used even w/o HW flow control with RTS/CTS.
So it need to be initialized and enabled earlier.

Signed-off-by: Anton Bondarenko <anton_bondarenko@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.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 d097169e85d1da77caeddae852f0b20d11a62916..ab958a59cae99f73a2d7b282650a38522403f896 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1141,12 +1141,20 @@ static int imx_startup(struct uart_port *port)
        while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
                udelay(1);
 
+       /* Can we enable the DMA support? */
+       if (is_imx6q_uart(sport) && !uart_console(port) &&
+           !sport->dma_is_inited)
+               imx_uart_dma_init(sport);
+
        spin_lock_irqsave(&sport->port.lock, flags);
        /*
         * Finally, clear and enable interrupts
         */
        writel(USR1_RTSD, sport->port.membase + USR1);
 
+       if (sport->dma_is_inited && !sport->dma_is_enabled)
+               imx_enable_dma(sport);
+
        temp = readl(sport->port.membase + UCR1);
        temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
 
@@ -1326,11 +1334,6 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
                if (sport->have_rtscts) {
                        ucr2 &= ~UCR2_IRTS;
                        ucr2 |= UCR2_CTSC;
-
-                       /* Can we enable the DMA support? */
-                       if (is_imx6q_uart(sport) && !uart_console(port)
-                               && !sport->dma_is_inited)
-                               imx_uart_dma_init(sport);
                } else {
                        termios->c_cflag &= ~CRTSCTS;
                }
@@ -1452,8 +1455,6 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
        if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
                imx_enable_ms(&sport->port);
 
-       if (sport->dma_is_inited && !sport->dma_is_enabled)
-               imx_enable_dma(sport);
        spin_unlock_irqrestore(&sport->port.lock, flags);
 }