Commit e802cbaf authored Oct 08, 2019 by Rasmus Villemoes Committed by Lee Jones Oct 14, 2019

backlight: pwm_bl: Eliminate a 64/32 division



lightness*1000 is nowhere near overflowing 32 bits, so we can just use
an ordinary 32/32 division, which is much cheaper than the 64/32 done
via do_div().

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

parent efdf690e

drivers/video/backlight/pwm_bl.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -178,7 +178,7 @@ static u64 cie1931(unsigned int lightness, unsigned int scale)
		*/
		lightness *= 100;
		if (lightness <= (8 * scale)) {
		retval = DIV_ROUND_CLOSEST_ULL(lightness * 10, 9033);
		retval = DIV_ROUND_CLOSEST(lightness * 10, 9033);
		} else {
		retval = int_pow((lightness + (16 * scale)) / 116, 3);
		retval = DIV_ROUND_CLOSEST_ULL(retval, (scale * scale));

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