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]> --- 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 -- 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/
