[PATCH 5.4 017/108] pwm: sprd: Ensure configuring period and duty_cycle isnt wrongly skipped

Greg Kroah-Hartman
2021-07-26T16:03:23Z

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ Upstream commit 65e2e6c1c20104ed19060a38f4edbf14e9f9a9a5 ]

As the last call to sprd_pwm_apply() might have exited early if
state->enabled was false, the values for period and duty_cycle stored in
pwm->state might not have been written to hardware and it must be
ensured that they are configured before enabling the PWM.

Fixes: 8aae4b02e8a6 ("pwm: sprd: Add Spreadtrum PWM support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pwm/pwm-sprd.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/pwm-sprd.c b/drivers/pwm/pwm-sprd.c
index be2394227423..892d853d48a1 100644
--- a/drivers/pwm/pwm-sprd.c
+++ b/drivers/pwm/pwm-sprd.c
@@ -180,13 +180,10 @@ static int sprd_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
}
}

- if (state->period != cstate->period ||
- state->duty_cycle != cstate->duty_cycle) {
- ret = sprd_pwm_config(spc, pwm, state->duty_cycle,
- state->period);
- if (ret)
- return ret;
- }
+ ret = sprd_pwm_config(spc, pwm, state->duty_cycle,
+ state->period);
+ if (ret)
+ return ret;

sprd_pwm_write(spc, pwm->hwpwm, SPRD_PWM_ENABLE, 1);
} else if (cstate->enabled) {
--
2.30.2