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authorYu Tu <yu.tu@amlogic.com>2022-04-07 16:13:53 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-15 11:28:10 +0200
commit368ab68b18de104719f386a5cfe3595673cc96de (patch)
treea576769b69462d0428bb1bf09eb368c23de13511
parentdt-bindings: serial: Update Qualcomm geni based QUP UART bindings (diff)
downloadwireguard-linux-368ab68b18de104719f386a5cfe3595673cc96de.tar.xz
wireguard-linux-368ab68b18de104719f386a5cfe3595673cc96de.zip
tty: serial: meson: Use DIV_ROUND_CLOSEST to calculate baud rates
Due to chip process differences, chip designers recommend using baud rates as close to and larger as possible in order to reduce clock errors. Signed-off-by: Yu Tu <yu.tu@amlogic.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lore.kernel.org/r/20220407081355.13602-2-yu.tu@amlogic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/meson_uart.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 2bf1c57e0981..8e59624935af 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -299,10 +299,10 @@ static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
cpu_relax();
if (port->uartclk == 24000000) {
- val = ((port->uartclk / 3) / baud) - 1;
+ val = DIV_ROUND_CLOSEST(port->uartclk / 3, baud) - 1;
val |= AML_UART_BAUD_XTAL;
} else {
- val = ((port->uartclk * 10 / (baud * 4) + 5) / 10) - 1;
+ val = DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1;
}
val |= AML_UART_BAUD_USE;
writel(val, port->membase + AML_UART_REG5);