[PATCH 4.19 282/421] serial: mvebu-uart: fix calculation of clock divisor

Greg Kroah-Hartman
2021-07-19T16:22:08Z

From: Pali Rohár <pali@kernel.org>

commit 9078204ca5c33ba20443a8623a41a68a9995a70d upstream.

The clock divisor should be rounded to the closest value.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: 68a0db1d7da2 ("serial: mvebu-uart: add function to change baudrate")
Cc: stable@vger.kernel.org # 0e4cf69ede87 ("serial: mvebu-uart: clarify the baud rate derivation")
Link: https://lore.kernel.org/r/20210624224909.6350-2-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/serial/mvebu-uart.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -462,7 +462,7 @@ static int mvebu_uart_baud_rate_set(stru
* makes use of D to configure the desired baudrate.
*/
m_divisor = OSAMP_DEFAULT_DIVISOR;
- d_divisor = DIV_ROUND_UP(port->uartclk, baud * m_divisor);
+ d_divisor = DIV_ROUND_CLOSEST(port->uartclk, baud * m_divisor);

brdv = readl(port->membase + UART_BRDV);
brdv &= ~BRDV_BAUD_MASK;