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Commit 0711d857 authored by Sonic Zhang's avatar Sonic Zhang Committed by Bryan Wu
Browse files

Blackfin Serial Driver: Fix bug - Increase buffer tail immediately before starting tx dma. 

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=2920



Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
parent db288381

drivers/serial/bfin_5xx.c

+18 −14
Original line number Diff line number Diff line
@@ -64,15 +64,20 @@ 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;

	struct circ_buf *xmit = &uart->port.info->xmit;

#if !defined(CONFIG_BF54x) && !defined(CONFIG_SERIAL_BFIN_DMA)

	unsigned short ier;

#endif



	while (!(UART_GET_LSR(uart) & TEMT))

		continue;

		cpu_relax();



#ifdef CONFIG_SERIAL_BFIN_DMA

	disable_dma(uart->tx_dma_channel);

	xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);

	uart->port.icount.tx += uart->tx_count;

	uart->tx_count = 0;

	uart->tx_done = 1;

#else

#ifdef CONFIG_BF54x

	/* Clear TFI bit */
@@ -94,6 +99,7 @@ static void bfin_serial_start_tx(struct uart_port *port) 
	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;



#ifdef CONFIG_SERIAL_BFIN_DMA

	if (uart->tx_done)

		bfin_serial_dma_tx_chars(uart);

#else

#ifdef CONFIG_BF54x
@@ -389,12 +395,10 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 
	unsigned short ier;

	int flags = 0;



	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_count = 0;

		uart->tx_done = 1;

		return;

	}
@@ -428,9 +432,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 
	set_dma_x_modify(uart->tx_dma_channel, 1);

	enable_dma(uart->tx_dma_channel);



	xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);

	uart->port.icount.tx += uart->tx_count;



#ifdef CONFIG_BF54x

	UART_SET_IER(uart, ETBEI);

#else
@@ -515,8 +516,8 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id) 


	spin_lock(&uart->port.lock);

	if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {

		clear_dma_irqstat(uart->tx_dma_channel);

		disable_dma(uart->tx_dma_channel);

		clear_dma_irqstat(uart->tx_dma_channel);

#ifdef CONFIG_BF54x

		UART_CLEAR_IER(uart, ETBEI);

#else
@@ -527,7 +528,8 @@ 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);



		uart->tx_done = 1;

		xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);

		uart->port.icount.tx += uart->tx_count;



		bfin_serial_dma_tx_chars(uart);

	}
@@ -542,12 +544,14 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id) 
	unsigned short irqstat;



	uart->rx_dma_nrows++;

	if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {

		uart->rx_dma_nrows = 0;

		uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;

	uart->rx_dma_buf.tail = DMA_RX_XCOUNT * uart->rx_dma_nrows;

	bfin_serial_dma_rx_chars(uart);

		uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;

	if (uart->rx_dma_nrows >= DMA_RX_YCOUNT) {

		uart->rx_dma_nrows = 0;

		uart->rx_dma_buf.tail = 0;

	}

	uart->rx_dma_buf.head = uart->rx_dma_buf.tail;



	spin_lock(&uart->port.lock);

	irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);

	clear_dma_irqstat(uart->rx_dma_channel);