diff mbox series

[v9,3/3] pwm: sifive: Fix the error in the idempotent test within the pwm_apply_state_debug function

Message ID 20240222081231.213406-4-nylon.chen@sifive.com
State New
Headers
Series Change PWM-controlled LED pin active mode and algorithm |

Commit Message

Nylon Chen Feb. 22, 2024, 8:12 a.m. UTC 
  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@sifive.com>
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Nylon Chen <nylon.chen@sifive.com>
---
 drivers/pwm/pwm-sifive.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

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);
 }