Commit 62f676ff authored by Jochen Mades's avatar Jochen Mades Committed by Greg Kroah-Hartman
Browse files

serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl 



Commit 8d479237 ("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.

Fixes: 8d479237 ("serial: amba-pl011: add RS485 support")
Cc: stable@vger.kernel.org # v5.15+
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: default avatarJochen Mades <jochen@mades.net>
[lukas: copyedit commit message, add stable designation]
Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/85fa3323ba8c307943969b7343e23f34c3e652ba.1642909284.git.lukas@wunner.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 037b91ec

drivers/tty/serial/amba-pl011.c

+6 −2
Original line number Diff line number Diff line
@@ -1582,8 +1582,12 @@ 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)

	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);