Le 28/05/2016 00:54, Alexandre Belloni a écrit :
> When using DMA, half duplex doesn't work properly because rx is not stopped
> before starting tx. Ensure we call atmel_stop_rx() in the DMA case.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
We can also add:
Cc: <stable@xxxxxxxxxxxxxxx> # v4.3+
Thanks Alexandre!
> ---
> drivers/tty/serial/atmel_serial.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 954941dd8124..f9c798cba83f 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -482,19 +482,21 @@ static void atmel_start_tx(struct uart_port *port)
> {
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> - if (atmel_use_pdc_tx(port)) {
> - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN)
> - /* The transmitter is already running. Yes, we
> - really need this.*/
> - return;
> + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR)
> + & ATMEL_PDC_TXTEN))
> + /* The transmitter is already running. Yes, we
> + really need this.*/
> + return;
>
> + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
> if ((port->rs485.flags & SER_RS485_ENABLED) &&
> !(port->rs485.flags & SER_RS485_RX_DURING_TX))
> atmel_stop_rx(port);
>
> + if (atmel_use_pdc_tx(port))
> /* re-enable PDC transmit */
> atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN);
> - }
> +
> /* Enable interrupts */
> atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
> }
>
--
Nicolas Ferre
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