tty: serial: pch: don't crash if DMA enabled but not loaded

[cascardo/linux.git] / drivers / tty / serial / pch_uart.c

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 0aa2b52..6bb7e90 100644 (file)
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -1508,10 +1508,14 @@ static int pch_uart_verify_port(struct uart_port *port,
                        __func__);
                return -EOPNOTSUPP;
 #endif
-               dev_info(priv->port.dev, "PCH UART : Use DMA Mode\n");
-               if (!priv->use_dma)
+               if (!priv->use_dma) {
                        pch_request_dma(port);
-               priv->use_dma = 1;
+                       if (priv->chan_rx)
+                               priv->use_dma = 1;
+               }
+               dev_info(priv->port.dev, "PCH UART: %s\n",
+                               priv->use_dma ?
+                               "Use DMA Mode" : "No DMA");
        }
 
        return 0;