From 170a08ad3d1a184f3f84e5d56031541740c7f874 Mon Sep 17 00:00:00 2001 From: Hui Wang Date: Tue, 8 Mar 2022 19:00:42 +0800 Subject: [PATCH] serial: sc16is7xx: Clear RS485 bits in the shutdown [ Upstream commit 927728a34f11b5a27f4610bdb7068317d6fdc72a ] We tested RS485 function on an EVB which has SC16IS752, after finishing the test, we started the RS232 function test, but found the RTS is still working in the RS485 mode. That is because both startup and shutdown call port_update() to set the EFCR_REG, this will not clear the RS485 bits once the bits are set in the reconf_rs485(). To fix it, clear the RS485 bits in shutdown. Cc: Signed-off-by: Hui Wang Link: https://lore.kernel.org/r/20220308110042.108451-1-hui.wang@canonical.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/sc16is7xx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 0ab7880..e98aa7b 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1055,10 +1055,12 @@ static void sc16is7xx_shutdown(struct uart_port *port) /* Disable all interrupts */ sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0); - /* Disable TX/RX */ + /* Disable TX/RX, clear auto RS485 and RTS invert */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | - SC16IS7XX_EFCR_TXDISABLE_BIT, + SC16IS7XX_EFCR_TXDISABLE_BIT | + SC16IS7XX_EFCR_AUTO_RS485_BIT | + SC16IS7XX_EFCR_RTS_INVERT_BIT, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); -- 2.7.4