[PATCH] Bugfix RTS line config in RS485 mode is overwritten in pl011_set_mctrl() function.

From: jmades
Date: Fri Dec 31 2021 - 12:21:30 EST


Based on the "0001-serial-amba-pl011-add-RS485-support.patch" this change is necesarry otherwise the RTS-line will be pulled up in SER_RS485_RTS_BEFORE_SEND mode before sending data. This hinders the driver to receive data, f.ex. when the device is an RS485 slave device.

Signed-off-by: jmades <jochen@xxxxxxxxx>
---
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