serial: sh-sci: Fix TX buffer mapping leak

The mapped transmit buffer is never unmapped. This leaks quite some
mappings, as the mapping is done in uart_ops.startup(), i.e. every time
the device is opened. Unmap the buffer on device close.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5a528b8985052017688fd539219b103a04ed1585..4345aa422eed43a146ccd56642b99838b71cdc86 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1384,6 +1384,8 @@ static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
 
        s->chan_tx = NULL;
        s->cookie_tx = -EINVAL;
+       dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
+                        DMA_TO_DEVICE);
        dma_release_channel(chan);
        if (enable_pio)
                sci_start_tx(port);