serial: sh-sci: Stop acknowledging DMA transmit completions

As dmaengine_prep_slave_sg() is called with the DMA_CTRL_ACK flag set
for DMA transmit requests, there's no need to explicitly acknowledge DMA
transmit requests in the DMA transmit completion callback.

Hence remove the call to async_tx_ack(), and remove the now unused
dma_async_tx_descriptor pointer in the sci_port structure.

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 049036dfb6ddf32c25775e0f41603ed92b873c2c..1191a6c486640983c30857cf7a40526b07824b6b 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -104,7 +104,6 @@ struct sci_port {
        struct dma_chan                 *chan_rx;
 
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
-       struct dma_async_tx_descriptor  *desc_tx;
        struct dma_async_tx_descriptor  *desc_rx[2];
        dma_cookie_t                    cookie_tx;
        dma_cookie_t                    cookie_rx[2];
@@ -1285,9 +1284,6 @@ static void sci_dma_tx_complete(void *arg)
 
        port->icount.tx += s->tx_dma_len;
 
-       async_tx_ack(s->desc_tx);
-       s->desc_tx = NULL;
-
        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                uart_write_wakeup(port);
 
@@ -1528,7 +1524,6 @@ static void work_fn_tx(struct work_struct *work)
                                   DMA_TO_DEVICE);
 
        spin_lock_irq(&port->lock);
-       s->desc_tx = desc;
        desc->callback = sci_dma_tx_complete;
        desc->callback_param = s;
        spin_unlock_irq(&port->lock);