Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> 於 2024年4月12日 週五 下午3:05寫道： > > On Tue, Apr 02, 2024 at 10:01:39AM +0800, Nylon Chen wrote: > > Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> 於 2024年3月19日 週二 上午2:17寫道： > > > > > > Hello, > > > > > > On Thu, Feb 22, 2024 at 04:12:31PM +0800, Nylon Chen wrote: > > > > Round the result to the nearest whole number. This ensures that > > > > real_period is always a reasonable integer that is not lower than the > > > > actual value. > > > > > > > > e.g. > > > > $ echo 110 > /sys/devices/platform/led-controller-1/leds/d12/brightness > > > > $ .apply is not idempotent (ena=1 pol=0 1739692/4032985) -> (ena=1 pol=0 1739630/4032985) > > > > > > > > Co-developed-by: Zong Li <zong.li@xxxxxxxxxx> > > > > Signed-off-by: Zong Li <zong.li@xxxxxxxxxx> > > > > Signed-off-by: Nylon Chen <nylon.chen@xxxxxxxxxx> > > > > --- > > > > drivers/pwm/pwm-sifive.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c > > > > index a586cfe4191b..bebcbebacccd 100644 > > > > --- a/drivers/pwm/pwm-sifive.c > > > > +++ b/drivers/pwm/pwm-sifive.c > > > > @@ -101,7 +101,7 @@ static void pwm_sifive_update_clock(struct pwm_sifive_ddata *ddata, > > > > > > > > /* As scale <= 15 the shift operation cannot overflow. */ > > > > num = (unsigned long long)NSEC_PER_SEC << (PWM_SIFIVE_CMPWIDTH + scale); > > > > - ddata->real_period = div64_ul(num, rate); > > > > + ddata->real_period = DIV_ROUND_UP_ULL(num, rate); > > > > dev_dbg(ddata->chip.dev, > > > > "New real_period = %u ns\n", ddata->real_period); > > > > } > > Hi Uwe > > > > > > pwm_sifive_apply has a DIV64_U64_ROUND_CLOSEST(). I wonder if that needs > > > adaption, too?! > > According to my experiments, no adjustment is necessary. > > Did you enable PWM_DEBUG and tested with something like: > > seq 5000 100000 | while read p; do echo p > /sys/class/pwm/pwmchipX/pwmY/period; done > Hi Uwe, I apologize for the significant delay in responding to your query, I've now completed a thorough verification of the PWM_DEBUG functionality. The Period Testing: seq 5000 5000 100000 | while read p; do echo $p > /sys/class/pwm/pwmchip0/pwm0/period echo "Testing period: $p" done The Duty Cycle Testing: for percent in 0 25 50 75 100; do duty=$((100000 * percent / 100)) echo $duty > /sys/class/pwm/pwmchip0/pwm0/duty_cycle done - All period values from 5000ns to 100000ns were applied successfully - Various duty cycle ratios were tested without issues - Monitored dmesg output during tests - no kernel messages about wrong settings were observed Let me know if you need any additional test data or have other parameters you'd like me to verify. > and then verified that this test didn't result in kernel messages about > wrong settings? > > Best regards > Uwe > > -- > Pengutronix e.K. | Uwe Kleine-König | > Industrial Linux Solutions | https://www.pengutronix.de/ | -- ========================================== sifive system software team 陳伯綸 Cell phone: 0989057854 E-mail: nylon7717@xxxxxxxxx ==========================================
