3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> commit 0058f0871efe7b01c6f2b3046c68196ab73e96da upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.16: - Adjust context - Keep using UART_GET_PTSR()] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/tty/serial/atmel_serial.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -434,19 +434,21 @@ static void atmel_start_tx(struct uart_p { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_pdc_tx(port)) { - if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) - /* The transmitter is already running. Yes, we - really need this.*/ - return; + if (atmel_use_pdc_tx(port) && (UART_GET_PTSR(port) + & 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 ((atmel_port->rs485.flags & SER_RS485_ENABLED) && !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_stop_rx(port); + if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - } + /* Enable interrupts */ UART_PUT_IER(port, atmel_port->tx_done_mask); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html