pwm: meson: Don't disable PWM when setting duty repeatedly

[ Upstream commit a279345807e1e0ae79567a52cfdd9d30c9174a3c ]

There is an abnormally low about 20ms,when setting duty repeatedly.
Because setting the duty will disable PWM and then enable. Delete
this operation now.

Fixes: 211ed63075 ("pwm: Add support for Meson PWM Controller")
Signed-off-by: Bichao Zheng <bichao.zheng@amlogic.com>
[ Dropped code instead of hiding it behind a comment ]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/pwm/pwm-meson.c

@@ -325,11 +325,6 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (state->period != channel->state.period ||
 	    state->duty_cycle != channel->state.duty_cycle ||
 	    state->polarity != channel->state.polarity) {
-		if (channel->state.enabled) {
-			meson_pwm_disable(meson, pwm->hwpwm);
-			channel->state.enabled = false;
-		}
-
 		if (state->polarity != channel->state.polarity) {
 			if (state->polarity == PWM_POLARITY_NORMAL)
 				meson->inverter_mask |= BIT(pwm->hwpwm);