pwm: sprd: Ensure configuring period and duty_cycle isn't wrongly ski…

…pped

[ Upstream commit 65e2e6c ]

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: 8aae4b0 ("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

@@ -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) {