If another channel is already enabled period must not be modified. If
the requested period is smaller than this unchangable period the driver
is still supposed to search a duty_cycle according to the usual rounding
rules.
So don't set the duty_cycle to 0 but continue to determine an
appropriate value for ccr.
Fixes: deaba9cff809 ("pwm: stm32: Implementation of the waveform callbacks")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
drivers/pwm/pwm-stm32.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index a59de4de18b6..ec2c05c9ee7a 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -103,22 +103,16 @@ static int stm32_pwm_round_waveform_tohw(struct pwm_chip *chip,
if (ret)
goto out;
- /*
- * calculate the best value for ARR for the given PSC, refuse if
- * the resulting period gets bigger than the requested one.
- */
arr = mul_u64_u64_div_u64(wf->period_length_ns, rate,
(u64)NSEC_PER_SEC * (wfhw->psc + 1));
if (arr <= wfhw->arr) {
/*
- * requested period is small than the currently
+ * requested period is smaller than the currently
* configured and unchangable period, report back the smallest
- * possible period, i.e. the current state; Initialize
- * ccr to anything valid.
+ * possible period, i.e. the current state and return 1
+ * to indicate the wrong rounding direction.
*/
- wfhw->ccr = 0;
ret = 1;
- goto out;
}
} else {
--
2.47.2