[PATCH 5.9 352/757] serial: 8250: Discard RTS/DTS setting from clock update method

Greg Kroah-Hartman
2020-10-27T15:56:43Z

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 7718453e36960dadb8dc46f2b514b309659e1270 ]

It has been a mistake to add the MCR register RTS/DTS fields setting in
the generic method of the UART reference clock update. There is no point
in asserting these lines at that procedure. Just discard the
serial8250_out_MCR() mathod invocation from there then.

Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200923161950.6237-2-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/8250/8250_port.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index c71d647eb87a0..1259fb6b66b38 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2665,7 +2665,6 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)

serial8250_set_divisor(port, baud, quot, frac);
serial_port_out(port, UART_LCR, up->lcr);
- serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);

spin_unlock_irqrestore(&port->lock, flags);
serial8250_rpm_put(up);
--
2.25.1