atmel_serial: fix flow control bug

Fix the following problem, related to hardware flow control (CTS/RTS):
Transmitting while CTS line is asserted in DMA mode, due to not checking
for tx-stopped condition.

We found these problems while testing the UARTs with hardware
flow-control.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: "Andrew Victor" <avictor.za@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index d5efd6c77904..89362d733d62 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -579,7 +579,7 @@ static void atmel_tx_dma(struct uart_port *port)
         /* disable PDC transmit */
         UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
 
-        if (!uart_circ_empty(xmit)) {
+        if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
                 dma_sync_single_for_device(port->dev,
                                            pdc->dma_addr,
                                            pdc->dma_size,