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Commit 56f5de8f authored by Sonic Zhang's avatar Sonic Zhang Committed by Bryan Wu
Browse files

Blackfin Serial Driver: Fix bug - update tx dma buffer tail before wake up processes. 



Also make rx dma buffer work as a loop.

Signed-off-by: default avatarSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
parent 0711d857

drivers/serial/bfin_5xx.c

+29 −22
Original line number Diff line number Diff line
@@ -415,7 +415,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 
	 */

	bfin_serial_mctrl_check(uart);



	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))

		uart->tx_count = UART_XMIT_SIZE - xmit->tail;
@@ -439,7 +438,6 @@ static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart) 
	ier |= ETBEI;

	UART_PUT_IER(uart, ier);

#endif

	spin_unlock_irqrestore(&uart->port.lock, flags);

}



static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
@@ -450,7 +448,9 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart) 
	status = UART_GET_LSR(uart);

	UART_CLEAR_LSR(uart);



	uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;

	uart->port.icount.rx +=

		CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,

		UART_XMIT_SIZE);



	if (status & BI) {

		uart->port.icount.brk++;
@@ -476,10 +476,12 @@ static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart) 
	else

		flg = TTY_NORMAL;



	for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {

		if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))

			goto dma_ignore_char;

		uart_insert_char(&uart->port, status, OE, uart->rx_dma_buf.buf[i], flg);

	for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {

		if (i >= UART_XMIT_SIZE)

			i = 0;

		if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))

			uart_insert_char(&uart->port, status, OE,

				uart->rx_dma_buf.buf[i], flg);

	}



 dma_ignore_char:
@@ -492,16 +494,20 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart) 
	int flags = 0;



	spin_lock_irqsave(&uart->port.lock, flags);

	x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);

	uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);

	x_pos = get_dma_curr_xcount(uart->rx_dma_channel);

	uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;

	if (uart->rx_dma_nrows == DMA_RX_YCOUNT)

		uart->rx_dma_nrows = 0;

	x_pos = DMA_RX_XCOUNT - x_pos;

	if (x_pos == DMA_RX_XCOUNT)

		x_pos = 0;



	pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;



	if (pos>uart->rx_dma_buf.tail) {

		uart->rx_dma_buf.tail = pos;

	if (pos != uart->rx_dma_buf.tail) {

		uart->rx_dma_buf.head = pos;

		bfin_serial_dma_rx_chars(uart);

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

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

	}

	spin_unlock_irqrestore(&uart->port.lock, flags);

	uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
@@ -525,12 +531,12 @@ static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id) 
		ier &= ~ETBEI;

		UART_PUT_IER(uart, ier);

#endif

		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

			uart_write_wakeup(&uart->port);



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

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



		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)

			uart_write_wakeup(&uart->port);



		bfin_serial_dma_tx_chars(uart);

	}
@@ -542,15 +548,16 @@ static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id) 
{

	struct bfin_serial_port *uart = dev_id;

	unsigned short irqstat;

	int pos;



	uart->rx_dma_nrows++;

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

	uart->rx_dma_nrows = DMA_RX_YCOUNT -

		get_dma_curr_ycount(uart->rx_dma_channel);

	pos = DMA_RX_XCOUNT * uart->rx_dma_nrows;

	if (pos != uart->rx_dma_buf.tail) {

		uart->rx_dma_buf.head = pos;

		bfin_serial_dma_rx_chars(uart);

	if (uart->rx_dma_nrows >= DMA_RX_YCOUNT) {

		uart->rx_dma_nrows = 0;

		uart->rx_dma_buf.tail = 0;

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

	}

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



	spin_lock(&uart->port.lock);

	irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);