diff options
Diffstat (limited to 'drivers/tty/serial/atmel_serial.c')
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 168b10cad47b..fabbe76203bb 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -481,6 +481,14 @@ static void atmel_stop_tx(struct uart_port *port) /* disable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS); } + + /* + * Disable the transmitter. + * This is mandatory when DMA is used, otherwise the DMA buffer + * is fully transmitted. + */ + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS); + /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); @@ -513,6 +521,9 @@ static void atmel_start_tx(struct uart_port *port) /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); + + /* re-enable the transmitter */ + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN); } /* @@ -798,6 +809,11 @@ static void atmel_complete_tx_dma(void *arg) */ if (!uart_circ_empty(xmit)) atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); + else if ((port->rs485.flags & SER_RS485_ENABLED) && + !(port->rs485.flags & SER_RS485_RX_DURING_TX)) { + /* DMA done, stop TX, start RX for RS485 */ + atmel_start_rx(port); + } spin_unlock_irqrestore(&port->lock, flags); } @@ -900,12 +916,6 @@ static void atmel_tx_dma(struct uart_port *port) desc->callback = atmel_complete_tx_dma; desc->callback_param = atmel_port; atmel_port->cookie_tx = dmaengine_submit(desc); - - } else { - if (port->rs485.flags & SER_RS485_ENABLED) { - /* DMA done, stop TX, start RX for RS485 */ - atmel_start_rx(port); - } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) |