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: stable@vger.kernel.org Signed-off-by: Hui Wang hui.wang@canonical.com --- 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 3a6c68e19c80..6adc51d9ecf3 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);