serial: sh-sci: Make unsigned values in sci_baud_calc_hscif() unsigned

Move the -1 offset of br to the assignment to *brr, so br cannot become
negative anymore, and update the clamp() call. Now all unsigned values
in sci_baud_calc_hscif() can become unsigned.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index b9eb4b525c0a75712b7803b9ea0cb86395c1617c..77e0a582da44947fe0e170ce985594e190a28083 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1870,7 +1870,8 @@ static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
 static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr,
                                unsigned int *srr, unsigned int *cks)
 {
-       int sr, c, br, err, recv_margin;
+       unsigned int sr, br, c;
+       int err, recv_margin;
        int min_err = 1000; /* 100% */
        int recv_max_margin = 0;
 
@@ -1880,9 +1881,9 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr,
                for (c = 0; c <= 3; c++) {
                        /* integerized formulas from HSCIF documentation */
                        br = DIV_ROUND_CLOSEST(freq, (sr *
-                                             (1 << (2 * c + 1)) * bps)) - 1;
-                       br = clamp(br, 0, 255);
-                       err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr *
+                                             (1 << (2 * c + 1)) * bps));
+                       br = clamp(br, 1U, 256U);
+                       err = DIV_ROUND_CLOSEST(freq, (br * bps * sr *
                                               (1 << (2 * c + 1)) / 1000)) -
                                               1000;
                        /* Calc recv margin
@@ -1908,7 +1909,7 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr,
                        else
                                continue;
 
-                       *brr = br;
+                       *brr = br - 1;
                        *srr = sr - 1;
                        *cks = c;
                }