serial: 8250_dma: Provide default slave configuration parameters

Some slave channel parameters will be always the same. For
example, direction for the Rx channel will always be
DMA_DEV_TO_MEM and DMA_MEM_TO_DEV for Tx channel.

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

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index fdb6139e8c17..7046769608d4 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -149,8 +149,14 @@ int serial8250_request_dma(struct uart_8250_port *p)
         struct uart_8250_dma    *dma = p->dma;
         dma_cap_mask_t          mask;
 
-        dma->rxconf.src_addr = p->port.mapbase + UART_RX;
-        dma->txconf.dst_addr = p->port.mapbase + UART_TX;
+        /* Default slave configuration parameters */
+        dma->rxconf.direction           = DMA_DEV_TO_MEM;
+        dma->rxconf.src_addr_width      = DMA_SLAVE_BUSWIDTH_1_BYTE;
+        dma->rxconf.src_addr            = p->port.mapbase + UART_RX;
+
+        dma->txconf.direction           = DMA_MEM_TO_DEV;
+        dma->txconf.dst_addr_width      = DMA_SLAVE_BUSWIDTH_1_BYTE;
+        dma->txconf.dst_addr            = p->port.mapbase + UART_TX;
 
         dma_cap_zero(mask);
         dma_cap_set(DMA_SLAVE, mask);