From 0c66940d584d1aac92f6a78460dc0ba2efd3b7ba Mon Sep 17 00:00:00 2001 From: Yegor Yefremov Date: Thu, 24 Mar 2016 09:03:45 +0100 Subject: [PATCH] tty/serial/8250: fix RS485 half-duplex RX When in half-duplex mode RX will be disabled before TX, but not enabled after deactivating transmitter. This patch enables UART_IER_RLSI and UART_IER_RDI interrupts after TX is over. Cc: Matwey V. Kornilov Signed-off-by: Yegor Yefremov Fixes: e490c9144cfa ("tty: Add software emulated RS485 support for 8250") Acked-by: Matwey V. Kornilov Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index e213da01a3d7..00ad2637b08c 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1403,9 +1403,18 @@ static void __do_stop_tx_rs485(struct uart_8250_port *p) /* * Empty the RX FIFO, we are not interested in anything * received during the half-duplex transmission. + * Enable previously disabled RX interrupts. */ - if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) + if (!(p->port.rs485.flags & SER_RS485_RX_DURING_TX)) { serial8250_clear_fifos(p); + + serial8250_rpm_get(p); + + p->ier |= UART_IER_RLSI | UART_IER_RDI; + serial_port_out(&p->port, UART_IER, p->ier); + + serial8250_rpm_put(p); + } } static void serial8250_em485_handle_stop_tx(unsigned long arg)