From 3a13884abea08a5043b98d9374486ec859d1e03a Mon Sep 17 00:00:00 2001 From: Dimitris Lampridis Date: Thu, 13 Mar 2014 15:11:47 +0200 Subject: [PATCH] tty/serial: omap: empty the RX FIFO at the end of half-duplex TX Provided that the SER_RS485_RX_DURING_TX flag is not set, empty the RX FIFO to prevent reading back the transmitted data. Signed-off-by: Dimitris Lampridis Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/omap-serial.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 65abea2c6e47..dd8b1a5458ff 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -342,6 +342,12 @@ static void serial_omap_stop_tx(struct uart_port *port) if ((up->rs485.flags & SER_RS485_ENABLED) && !(up->rs485.flags & SER_RS485_RX_DURING_TX)) { + /* + * Empty the RX FIFO, we are not interested in anything + * received during the half-duplex transmission. + */ + serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_RCVR); + /* Re-enable RX interrupts */ up->ier |= UART_IER_RLSI | UART_IER_RDI; up->port.read_status_mask |= UART_LSR_DR; serial_out(up, UART_IER, up->ier); -- 2.20.1