| Message ID | 1405321800-18114-1-git-send-email-nobuhiro.iwamatsu.yj@renesas.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
On Mon, Jul 14, 2014 at 04:09:58PM +0900, Nobuhiro Iwamatsu wrote: > 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> All three patches: Acked-by: Simon Horman <horms+renesas@verge.net.au> > --- > drivers/tty/serial/sh-sci.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c > index 88236da..ce80137 100644 > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -1796,11 +1796,13 @@ 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; > -- > 2.0.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sh" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 88236da..ce80137 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1796,11 +1796,13 @@ 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;
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> --- drivers/tty/serial/sh-sci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)