[PATCH] tty/serial: atmel: fix out of range clock divider handling

From: David Engraf
Date: Wed Dec 11 2019 - 11:30:24 EST


Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode
register was already written thus the clock selection is ignored.

Fix by writing the mode register after calculating the baudrate.

Signed-off-by: David Engraf <david.engraf@xxxxxxxxx>
---
drivers/tty/serial/atmel_serial.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index a8dc8af83f39..9983e2fabbac 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2270,9 +2270,6 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
mode |= ATMEL_US_USMODE_NORMAL;
}

- /* set the mode, clock divisor, parity, stop bits and data size */
- atmel_uart_writel(port, ATMEL_US_MR, mode);
-
/*
* when switching the mode, set the RTS line state according to the
* new mode, otherwise keep the former state
@@ -2315,6 +2312,9 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
}
quot = cd | fp << ATMEL_US_FP_OFFSET;

+ /* set the mode, clock divisor, parity, stop bits and data size */
+ atmel_uart_writel(port, ATMEL_US_MR, mode);
+
if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
atmel_uart_writel(port, ATMEL_US_BRGR, quot);
atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
--
2.17.1