From 90690b3e8afbdfbbb5ceb0f6cef40ed282b1c004 Mon Sep 17 00:00:00 2001 From: jmades Date: Mon, 27 Dec 2021 08:37:26 +0000 Subject: [PATCH] serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl Commit 8d479237727c ("serial: amba-pl011: add RS485 support") sought to keep RTS deasserted on set_mctrl if rs485 is enabled. However it did so only if deasserted RTS polarity is high. Fix it in case it's low. Signed-off-by: jmades --- drivers/tty/serial/amba-pl011.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 537f37ac4..1749c1498 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1646,8 +1646,12 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) container_of(port, struct uart_amba_port, port); unsigned int cr; - if (port->rs485.flags & SER_RS485_ENABLED) - mctrl &= ~TIOCM_RTS; + if (port->rs485.flags & SER_RS485_ENABLED) { + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) + mctrl &= ~TIOCM_RTS; + else + mctrl |= TIOCM_RTS; + } cr = pl011_read(uap, REG_CR); -- 2.20.1