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    SubjectRe: [PATCH] atmel_serial: RS485: receiving enabled when sending data
    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@pwrnet.de>
    > Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
    > ---
    > 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


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