On Mon, Aug 15, 2011 at 04:28:15PM +0200, Bernhard Roth wrote: > Hello! > > By default the atmel_serial driver in RS485 mode disables receiving > data until all data in the send buffer has been sent. This flag > allows to receive data even whilst sending data. This is very useful > to > > - check if the data has been sent correctly over the RS485 bus > - assure that no collision happened > - check for short circuits/termination issues on the RS485 bus > > Usually this functionality is realized by hardware, wether > controlling the RX-Enable pin of the RS485 transceiver with RTS > (driver control signal) or pulling it LOW permanently. The present > atmel_serial driver makes this impossible, thus requiring following > patch. > > Usage example: > > struct serial_rs485 rs485; > > memset(&rs485, 0, sizeof(rs485)); > rs485.flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX; > ioctl(fd, TIOCSRS485, &rs485); > > > > > atmel_serial: RS485: receiving enabled when sending data > > By default the atmel_serial driver in RS485 mode disables receiving > data until > all data in the send buffer has been sent. This flag allows to receive data > even whilst sending data. > > Signed-off-by: Bernhard Roth <br@xxxxxxxxx> > Signed-off-by: Claudio Scordino <claudio@xxxxxxxxxxxxxxx> > --- > drivers/tty/serial/atmel_serial.c | 17 ++++++++++------- > include/linux/serial.h | 1 + > 2 files changed, 11 insertions(+), 7 deletions(-) > > diff --git a/drivers/tty/serial/atmel_serial.c > b/drivers/tty/serial/atmel_serial.c > index af9b781..5f6c745 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -339,8 +339,9 @@ static void atmel_stop_tx(struct uart_port *port) > /* Disable interrupts */ > UART_PUT_IDR(port, atmel_port->tx_done_mask); > > - if (atmel_port->rs485.flags & SER_RS485_ENABLED) > - atmel_start_rx(port); > + if ((atmel_port->rs485.flags & SER_RS485_ENABLED) && > + !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) > + atmel_start_rx(port); Can you fix your email client to not strip patches of tabs and resend this so that I can apply it? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
