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| author | Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> | 2014-07-14 09:09:58 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-18 03:14:44 +0200 |
| commit | b7d66397f4d282ddf2a2fe516fc9329c5a063459 (patch) | |
| tree | e67a8ab952b337f4858a37d6ada0a0a46af5f172 /drivers/tty | |
| parent | Merge 3.16-rc5 into tty-next. (diff) | |
| download | linux-b7d66397f4d282ddf2a2fe516fc9329c5a063459.tar.xz linux-b7d66397f4d282ddf2a2fe516fc9329c5a063459.zip | |
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: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 26dad3e87b52..2ba42069922f 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -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; |