serial: 8250_dma: check the result of TX buffer mapping

Using dma_mapping_error() to make sure the mapping did not
fail.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index ab9096dc384976de15c41f0d5f39b6975b72a45d..148ffe4c232f6bd8322d3387d41f227d5d811263 100644 (file)
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -192,21 +192,28 @@ int serial8250_request_dma(struct uart_8250_port *p)
 
        dma->rx_buf = dma_alloc_coherent(dma->rxchan->device->dev, dma->rx_size,
                                        &dma->rx_addr, GFP_KERNEL);
-       if (!dma->rx_buf) {
-               dma_release_channel(dma->rxchan);
-               dma_release_channel(dma->txchan);
-               return -ENOMEM;
-       }
+       if (!dma->rx_buf)
+               goto err;
 
        /* TX buffer */
        dma->tx_addr = dma_map_single(dma->txchan->device->dev,
                                        p->port.state->xmit.buf,
                                        UART_XMIT_SIZE,
                                        DMA_TO_DEVICE);
+       if (dma_mapping_error(dma->txchan->device->dev, dma->tx_addr)) {
+               dma_free_coherent(dma->rxchan->device->dev, dma->rx_size,
+                                 dma->rx_buf, dma->rx_addr);
+               goto err;
+       }
 
        dev_dbg_ratelimited(p->port.dev, "got both dma channels\n");
 
        return 0;
+err:
+       dma_release_channel(dma->rxchan);
+       dma_release_channel(dma->txchan);
+
+       return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(serial8250_request_dma);