serial: sh-sci: Handle DMA init failures inside sci_request_dma()

Let sci_request_dma() handle failures to initialize DMA itself.
This way sci_tx_dma_release() and sci_rx_dma_release() don't have to
consider partial initialization, and thus don't need to reset DMA
addresses to DMA_ERROR_CODE, which is not 100% portable access
architectures.

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 cfef543df25271f5b36fc82aabd852e295931234..ea6ab6173ce9f2395c77987b65ce9f2aa161d7f0 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1371,9 +1371,8 @@ static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
        s->chan_rx = NULL;
        s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
        dma_release_channel(chan);
-       if (sg_dma_address(&s->sg_rx[0]))
-               dma_free_coherent(port->dev, s->buf_len_rx * 2,
-                                 sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
+       dma_free_coherent(port->dev, s->buf_len_rx * 2,
+                         sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
        if (enable_pio)
                sci_start_rx(port);
 }
@@ -1709,7 +1708,8 @@ static void sci_request_dma(struct uart_port *port)
                nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
                if (!nent) {
                        dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
-                       sci_tx_dma_release(s, false);
+                       dma_release_channel(chan);
+                       s->chan_tx = NULL;
                } else {
                        dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n",
                                __func__,
@@ -1743,7 +1743,9 @@ static void sci_request_dma(struct uart_port *port)
                if (!buf[0]) {
                        dev_warn(port->dev,
                                 "Failed to allocate Rx dma buffer, using PIO\n");
-                       sci_rx_dma_release(s, true);
+                       dma_release_channel(chan);
+                       s->chan_rx = NULL;
+                       sci_start_rx(port);
                        return;
                }