Hello, On Thu, Jan 25, 2024 at 10:55:30AM +0800, Wenhua Lin wrote: > diff --git a/drivers/pwm/pwm-sprd.c b/drivers/pwm/pwm-sprd.c > index cc54aa77c7e6..8de3f9e154ce 100644 > --- a/drivers/pwm/pwm-sprd.c > +++ b/drivers/pwm/pwm-sprd.c > @@ -156,7 +156,8 @@ static int sprd_pwm_config(struct sprd_pwm_chip *spc, struct pwm_device *pwm, > * given settings (MOD and input clock). > */ > mod = spc->mod[pwm->hwpwm]; > - duty = duty_ns * mod / period_ns; > + tmp = (u64)duty_ns * mod; > + duty = DIV_ROUND_CLOSEST_ULL(tmp, period_ns); Please stick to rounding down in .apply() (and so sprd_pwm_config()). Given that duty_ns is an u64 in .apply(), you're loosing precision anyhow. Look at how the microchip-core driver uses mul_u64_u64_div_u64() for how to do that properly. You tested your patch with CONFIG_PWM_DEBUG enabled, right? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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