[Blackfin] serial driver: Clean up UART DMA code.

Start next TX DMA in tx dma handler instead of rx timer handler.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index e059475c91ae803c318641ef0a0897991cd771ba..3a2aa7e277fa476379b2bf0b5c0fc2614f600b80 100644 (file)
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -84,7 +84,7 @@ static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
 static void bfin_serial_stop_tx(struct uart_port *port)
 {
        struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
-#ifndef CONFIG_BF54x
+#if !defined(CONFIG_BF54x) && !defined(CONFIG_SERIAL_BFIN_DMA)
        unsigned short ier;
 #endif
 
@@ -307,7 +307,6 @@ static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
                UART_PUT_CHAR(uart, uart->port.x_char);
                uart->port.icount.tx++;
                uart->port.x_char = 0;
-               return;
        }
        /*
         * Check the modem control lines before
@@ -376,28 +375,26 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
 
        if (!uart->tx_done)
                return;
-
        uart->tx_done = 0;
 
+       if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+               bfin_serial_stop_tx(&uart->port);
+               uart->tx_done = 1;
+               return;
+       }
+
        if (uart->port.x_char) {
                UART_PUT_CHAR(uart, uart->port.x_char);
                uart->port.icount.tx++;
                uart->port.x_char = 0;
-               uart->tx_done = 1;
-               return;
        }
+
        /*
         * Check the modem control lines before
         * transmitting anything.
         */
        bfin_serial_mctrl_check(uart);
 
-       if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
-               bfin_serial_stop_tx(&uart->port);
-               uart->tx_done = 1;
-               return;
-       }
-
        spin_lock_irqsave(&uart->port.lock, flags);
        uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
        if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
@@ -471,8 +468,6 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
        int x_pos, pos;
        int flags = 0;
 
-       bfin_serial_dma_tx_chars(uart);
-
        spin_lock_irqsave(&uart->port.lock, flags);
        x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
        if (x_pos == DMA_RX_XCOUNT)
@@ -513,9 +508,9 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
                if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                        uart_write_wakeup(&uart->port);
 
-               if (uart_circ_empty(xmit))
-                       bfin_serial_stop_tx(&uart->port);
                uart->tx_done = 1;
+
+               bfin_serial_dma_tx_chars(uart);
        }
 
        spin_unlock(&uart->port.lock);