[PATCH] atmel_serial: Fix roundoff error in atmel_console_get_options

[firefly-linux-kernel-4.4.55.git] / drivers / serial / atmel_serial.c

diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 61db2166fbb509c34309b01d4f8e62f0fcba5f58..955c46da580041de800d8ced1cc5c23af2b60dda 100644 (file)
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -793,8 +793,14 @@ static void __init atmel_console_get_options(struct uart_port *port, int *baud,
        else if (mr == ATMEL_US_PAR_ODD)
                *parity = 'o';
 
+       /*
+        * The serial core only rounds down when matching this to a
+        * supported baud rate. Make sure we don't end up slightly
+        * lower than one of those, as it would make us fall through
+        * to a much lower baud rate than we really want.
+        */
        quot = UART_GET_BRGR(port);
-       *baud = port->uartclk / (16 * (quot));
+       *baud = port->uartclk / (16 * (quot - 1));
 }
 
 static int __init atmel_console_setup(struct console *co, char *options)