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Commit b7d66397 authored by Nobuhiro Iwamatsu's avatar Nobuhiro Iwamatsu Committed by Greg Kroah-Hartman
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serial: sh-sci: Updated calculation of bit error rate and bit rate 



Currently, the decimal point is discarded calculation of BRR.
Therefore, it can not calculate a value close to the correct value.
This patch fixes this problem by using DIV_ROUND_CLOSEST.

Signed-off-by: default avatarNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ca177492

drivers/tty/serial/sh-sci.c

+5 −3
Original line number Diff line number Diff line
@@ -1789,11 +1789,13 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, 
	for (sr = 8; sr <= 32; sr++) {

		for (c = 0; c <= 3; c++) {

			/* integerized formulas from HSCIF documentation */

			br = freq / (sr * (1 << (2 * c + 1)) * bps) - 1;

			br = DIV_ROUND_CLOSEST(freq, (sr *

					      (1 << (2 * c + 1)) * bps)) - 1;

			if (br < 0 || br > 255)

				continue;

			err = freq / ((br + 1) * bps * sr *

			      (1 << (2 * c + 1)) / 1000) - 1000;

			err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr *

					       (1 << (2 * c + 1)) / 1000)) -

					       1000;

			if (min_err > err) {

				min_err = err;

				*brr = br;