From 52a6ba0b4a6efb04557c64e5c90bcd1b97c1238e Mon Sep 17 00:00:00 2001 From: David Engraf Date: Mon, 16 Dec 2019 09:54:03 +0100 Subject: tty/serial: atmel: fix out of range clock divider handling [ Upstream commit cb47b9f8630ae3fa3f5fbd0c7003faba7abdf711 ] Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode register was already written thus the clock selection is ignored. Fix by doing the baud rate calulation before setting the mode. Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support") Signed-off-by: David Engraf Acked-by: Ludovic Desroches Acked-by: Richard Genoud Cc: stable Link: https://lore.kernel.org/r/20191216085403.17050-1-david.engraf@sysgo.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/atmel_serial.c | 43 ++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 21 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 9ee41ba0e55b..367ce812743e 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2183,27 +2183,6 @@ 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 - */ - if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { - unsigned int rts_state; - - if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { - /* let the hardware control the RTS line */ - rts_state = ATMEL_US_RTSDIS; - } else { - /* force RTS line to low level */ - rts_state = ATMEL_US_RTSEN; - } - - atmel_uart_writel(port, ATMEL_US_CR, rts_state); - } - /* * Set the baud rate: * Fractional baudrate allows to setup output frequency more @@ -2229,6 +2208,28 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, quot = cd | fp << ATMEL_US_FP_OFFSET; atmel_uart_writel(port, ATMEL_US_BRGR, quot); + + /* 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 + */ + if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { + unsigned int rts_state; + + if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { + /* let the hardware control the RTS line */ + rts_state = ATMEL_US_RTSDIS; + } else { + /* force RTS line to low level */ + rts_state = ATMEL_US_RTSEN; + } + + atmel_uart_writel(port, ATMEL_US_CR, rts_state); + } + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); -- cgit v1.2.3