pch_uart: Fix duplicate memory release issue

Add initialize variable to prevent duplicate free memory.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index e7d91d973d52..6e96304b7c8f 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -656,10 +656,13 @@ static void pch_free_dma(struct uart_port *port)
                 dma_release_channel(priv->chan_rx);
                 priv->chan_rx = NULL;
         }
-        if (sg_dma_address(&priv->sg_rx))
-                dma_free_coherent(port->dev, port->fifosize,
-                                  sg_virt(&priv->sg_rx),
-                                  sg_dma_address(&priv->sg_rx));
+
+        if (priv->rx_buf_dma) {
+                dma_free_coherent(port->dev, port->fifosize, priv->rx_buf_virt,
+                                  priv->rx_buf_dma);
+                priv->rx_buf_virt = NULL;
+                priv->rx_buf_dma = 0;
+        }
 
         return;
 }