pch_uart: fix exclusive access issue

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 0c95051fa0a4..da0ba0fa2b99 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -636,8 +636,7 @@ static void pch_dma_tx_complete(void *arg)
         priv->tx_dma_use = 0;
         priv->nent = 0;
         kfree(priv->sg_tx_p);
-        if (uart_circ_chars_pending(xmit))
-                pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
+        pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
 }
 
 static int pop_tx(struct eg20t_port *priv, int size)
@@ -793,6 +792,14 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
                 return 0;
         }
 
+        if (priv->tx_dma_use) {
+                dev_dbg(priv->port.dev, "%s:Tx is not completed. (%lu)\n",
+                        __func__, jiffies);
+                pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+                priv->tx_empty = 1;
+                return 0;
+        }
+
         fifo_size = max(priv->fifo_size, 1);
         tx_empty = 1;
         if (pop_tx_x(priv, xmit->buf)) {