diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_dma.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dma.c | 39 |
1 files changed, 25 insertions, 14 deletions
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c index 148ffe4c232f..fcd7ac6af2fc 100644 --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -21,6 +21,7 @@ static void __dma_tx_complete(void *param) struct uart_8250_dma *dma = p->dma; struct circ_buf *xmit = &p->port.state->xmit; unsigned long flags; + int ret; dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); @@ -36,8 +37,11 @@ static void __dma_tx_complete(void *param) if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&p->port); - if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) - serial8250_tx_dma(p); + ret = serial8250_tx_dma(p); + if (ret) { + p->ier |= UART_IER_THRI; + serial_port_out(&p->port, UART_IER, p->ier); + } spin_unlock_irqrestore(&p->port.lock, flags); } @@ -53,6 +57,7 @@ static void __dma_rx_complete(void *param) dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr, dma->rx_size, DMA_FROM_DEVICE); + dma->rx_running = 0; dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); dmaengine_terminate_all(dma->rxchan); @@ -69,6 +74,7 @@ int serial8250_tx_dma(struct uart_8250_port *p) struct uart_8250_dma *dma = p->dma; struct circ_buf *xmit = &p->port.state->xmit; struct dma_async_tx_descriptor *desc; + int ret; if (uart_tx_stopped(&p->port) || dma->tx_running || uart_circ_empty(xmit)) @@ -80,11 +86,12 @@ int serial8250_tx_dma(struct uart_8250_port *p) dma->tx_addr + xmit->tail, dma->tx_size, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc) - return -EBUSY; + if (!desc) { + ret = -EBUSY; + goto err; + } dma->tx_running = 1; - desc->callback = __dma_tx_complete; desc->callback_param = p; @@ -94,19 +101,23 @@ int serial8250_tx_dma(struct uart_8250_port *p) UART_XMIT_SIZE, DMA_TO_DEVICE); dma_async_issue_pending(dma->txchan); - + if (dma->tx_err) { + dma->tx_err = 0; + if (p->ier & UART_IER_THRI) { + p->ier &= ~UART_IER_THRI; + serial_out(p, UART_IER, p->ier); + } + } return 0; +err: + dma->tx_err = 1; + return ret; } -EXPORT_SYMBOL_GPL(serial8250_tx_dma); int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) { struct uart_8250_dma *dma = p->dma; struct dma_async_tx_descriptor *desc; - struct dma_tx_state state; - int dma_status; - - dma_status = dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); switch (iir & 0x3f) { case UART_IIR_RLSI: @@ -117,7 +128,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) * If RCVR FIFO trigger level was not reached, complete the * transfer and let 8250_core copy the remaining data. */ - if (dma_status == DMA_IN_PROGRESS) { + if (dma->rx_running) { dmaengine_pause(dma->rxchan); __dma_rx_complete(p); } @@ -126,7 +137,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) break; } - if (dma_status) + if (dma->rx_running) return 0; desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, @@ -135,6 +146,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) if (!desc) return -EBUSY; + dma->rx_running = 1; desc->callback = __dma_rx_complete; desc->callback_param = p; @@ -147,7 +159,6 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir) return 0; } -EXPORT_SYMBOL_GPL(serial8250_rx_dma); int serial8250_request_dma(struct uart_8250_port *p) { |