Using result = (value + divisor/2) / divisor is rounding values up and only works well for positive values. Instead use DIV_ROUND_CLOSEST which does the correct thing.
Signed-off-by: Alexandre Belloni <[email protected]> --- drivers/rtc/rtc-pcf2123.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c index 39da8b214275..80a53d2dc813 100644 --- a/drivers/rtc/rtc-pcf2123.c +++ b/drivers/rtc/rtc-pcf2123.c @@ -244,7 +244,7 @@ static int pcf2123_set_offset(struct device *dev, long offset) else if (offset < OFFSET_STEP * -128) reg = -128; else - reg = (s8)((offset + (OFFSET_STEP >> 1)) / OFFSET_STEP); + reg = DIV_ROUND_CLOSEST(offset, OFFSET_STEP); /* choose fine offset only for odd values in the normal range */ if (reg & 1 && reg <= 63 && reg >= -64) { -- 2.21.0
