On Sat, 24 Nov 2012, Axel Lin wrote: > Below equation means the "voltage" is the "smallest" voltage within specific > range. > > ret = DIV_ROUND_UP(min - bottom) / step; > voltage = ret * step + bottom; > > If we do try 1 down when (voltage > max), new voltage is then less than min > voltage. Which means the new voltage is not in the requested voltage range. > > This patch also includes below cleanups: > - Use DIV_ROUND_UP > - rename variable 'ret' to 'sel' for better readability because > as3711_sel_check > returns the selector. > > Signed-off-by: Axel Lin <[email protected]>
Acked-by: Guennadi Liakhovetski <[email protected]> Thanks Guennadi > --- > drivers/regulator/as3711-regulator.c | 23 ++++++++--------------- > 1 file changed, 8 insertions(+), 15 deletions(-) > > diff --git a/drivers/regulator/as3711-regulator.c > b/drivers/regulator/as3711-regulator.c > index 5e813b9..2f1341d 100644 > --- a/drivers/regulator/as3711-regulator.c > +++ b/drivers/regulator/as3711-regulator.c > @@ -93,24 +93,17 @@ static int as3711_bound_check(struct regulator_dev *rdev, > > static int as3711_sel_check(int min, int max, int bottom, int step) > { > - int ret, voltage; > + int sel, voltage; > > /* Round up min, when dividing: keeps us within the range */ > - ret = (min - bottom + step - 1) / step; > - voltage = ret * step + bottom; > + sel = DIV_ROUND_UP(min - bottom, step); > + voltage = sel * step + bottom; > pr_debug("%s(): select %d..%d in %d+N*%d: %d\n", __func__, > - min, max, bottom, step, ret); > - if (voltage > max) { > - /* > - * Try 1 down. It will take us below min, but as long we stay > - * above bottom, we're fine. > - */ > - ret--; > - voltage = ret * step + bottom; > - if (voltage < bottom) > - return -EINVAL; > - } > - return ret; > + min, max, bottom, step, sel); > + if (voltage > max) > + return -EINVAL; > + > + return sel; > } > > static int as3711_map_voltage_sd(struct regulator_dev *rdev, > -- > 1.7.9.5 > > > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
