Blackfin Serial Driver: fix error while transferring large files (8516c568) · Commits · 戴 / test

drivers/serial/bfin_5xx.c

+29 −2

Original line number	Diff line number	Diff line
		@@ -477,6 +477,15 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)

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

		/* 2D DMA RX buffer ring is used. Because curr_y_count and
		* curr_x_count can't be read as an atomic operation,
		* curr_y_count should be read before curr_x_count. When
		* curr_x_count is read, curr_y_count may already indicate
		* next buffer line. But, the position calculated here is
		* still indicate the old line. The wrong position data may
		* be smaller than current buffer tail, which cause garbages
		* are received if it is not prohibit.
		*/
		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;
		@@ -487,7 +496,11 @@ void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
		x_pos = 0;

		pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
		if (pos != uart->rx_dma_buf.tail) {
		/* Ignore receiving data if new position is in the same line of
		* current buffer tail and small.
		*/
		if (pos > uart->rx_dma_buf.tail \|\|
		uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
		uart->rx_dma_buf.head = pos;
		bfin_serial_dma_rx_chars(uart);
		uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
		@@ -532,11 +545,25 @@ 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;

		spin_lock(&uart->port.lock);
		irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
		clear_dma_irqstat(uart->rx_dma_channel);

		uart->rx_dma_nrows = get_dma_curr_ycount(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;

		pos = uart->rx_dma_nrows * DMA_RX_XCOUNT;
		if (pos > uart->rx_dma_buf.tail \|\|
		uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
		uart->rx_dma_buf.head = pos;
		bfin_serial_dma_rx_chars(uart);
		uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
		}

		spin_unlock(&uart->port.lock);

		return IRQ_HANDLED;

Admin message