Re: [PATCH 2/2] serial: 8250-mtk: modify uart DMA rx

Long Cheng
2019-05-30T09:34:45Z

On Thu, 2019-05-23 at 15:35 +0800, Long Cheng wrote:

Hi Greg,

Just a gentle ping!

thanks.

> Modify uart rx and complete for DMA
>
> Signed-off-by: Long Cheng <long.cheng@mediatek.com>
> ---
> drivers/tty/serial/8250/8250_mtk.c | 49 +++++++++++++++---------------------
> 1 file changed, 20 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> index 417c7c8..f470ded 100644
> --- a/drivers/tty/serial/8250/8250_mtk.c
> +++ b/drivers/tty/serial/8250/8250_mtk.c
> @@ -47,7 +47,6 @@
> #define MTK_UART_DMA_EN_RX 0x5
>
> #define MTK_UART_ESCAPE_CHAR 0x77 /* Escape char added under sw fc */
> -#define MTK_UART_TX_SIZE UART_XMIT_SIZE
> #define MTK_UART_RX_SIZE 0x8000
> #define MTK_UART_TX_TRIGGER 1
> #define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE
> @@ -89,28 +88,30 @@ static void mtk8250_dma_rx_complete(void *param)
> struct mtk8250_data *data = up->port.private_data;
> struct tty_port *tty_port = &up->port.state->port;
> struct dma_tx_state state;
> + int copied, total, cnt;
> unsigned char *ptr;
> - int copied;
>
> - dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
> - dma->rx_size, DMA_FROM_DEVICE);
> + if (data->rx_status == DMA_RX_SHUTDOWN)
> + return;
>
> dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
> + total = dma->rx_size - state.residue;
> + cnt = total;
>
> - if (data->rx_status == DMA_RX_SHUTDOWN)
> - return;
> + if ((data->rx_pos + cnt) > dma->rx_size)
> + cnt = dma->rx_size - data->rx_pos;
>
> - if ((data->rx_pos + state.residue) <= dma->rx_size) {
> - ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
> - copied = tty_insert_flip_string(tty_port, ptr, state.residue);
> - } else {
> - ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
> - copied = tty_insert_flip_string(tty_port, ptr,
> - dma->rx_size - data->rx_pos);
> + ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
> + copied = tty_insert_flip_string(tty_port, ptr, cnt);
> + data->rx_pos += cnt;
> +
> + if (total > cnt) {
> ptr = (unsigned char *)(dma->rx_buf);
> - copied += tty_insert_flip_string(tty_port, ptr,
> - data->rx_pos + state.residue - dma->rx_size);
> + cnt = total - cnt;
> + copied += tty_insert_flip_string(tty_port, ptr, cnt);
> + data->rx_pos = cnt;
> }
> +
> up->port.icount.rx += copied;
>
> tty_flip_buffer_push(tty_port);
> @@ -121,9 +122,7 @@ static void mtk8250_dma_rx_complete(void *param)
> static void mtk8250_rx_dma(struct uart_8250_port *up)
> {
> struct uart_8250_dma *dma = up->dma;
> - struct mtk8250_data *data = up->port.private_data;
> struct dma_async_tx_descriptor *desc;
> - struct dma_tx_state state;
>
> desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
> dma->rx_size, DMA_DEV_TO_MEM,
> @@ -138,12 +137,6 @@ static void mtk8250_rx_dma(struct uart_8250_port *up)
>
> dma->rx_cookie = dmaengine_submit(desc);
>
> - dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
> - data->rx_pos = state.residue;
> -
> - dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
> - dma->rx_size, DMA_FROM_DEVICE);
> -
> dma_async_issue_pending(dma->rxchan);
> }
>
> @@ -156,13 +149,11 @@ static void mtk8250_dma_enable(struct uart_8250_port *up)
> if (data->rx_status != DMA_RX_START)
> return;
>
> - dma->rxconf.direction = DMA_DEV_TO_MEM;
> - dma->rxconf.src_addr_width = dma->rx_size / 1024;
> - dma->rxconf.src_addr = dma->rx_addr;
> + dma->rxconf.src_port_window_size = dma->rx_size;
> + dma->rxconf.src_addr = dma->rx_addr;
>
> - dma->txconf.direction = DMA_MEM_TO_DEV;
> - dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024;
> - dma->txconf.dst_addr = dma->tx_addr;
> + dma->txconf.dst_port_window_size = UART_XMIT_SIZE;
> + dma->txconf.dst_addr = dma->tx_addr;
>
> serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
> UART_FCR_CLEAR_XMIT);