[PATCH 2/2] leds/pwm: Don't disable pwm when setting brightness to 0

[Uwe Kleine-König]

This fixes disabling the LED on i.MX28. The PWM hardware delays using
the newly set pwm-config until the beginning of a new period. It's very
likely that pwm_disable is called before the current period ends. In
case the LED was on brightness=max before the LED stays on because in
the disabled PWM block the period never ends.

Also only call pwm_enable only once in the probe call back and the
matching pwm_disable in .remove(). Moreover the pwm is explicitly
initialized to off.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 drivers/leds/leds-pwm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index f668500a2157..5dae0d2dc3dc 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -44,11 +44,6 @@ static void __led_pwm_set(struct led_pwm_data *led_dat)
 	int new_duty = led_dat->duty;
 
 	pwm_config(led_dat->pwm, new_duty, led_dat->period);
-
-	if (new_duty == 0)
-		pwm_disable(led_dat->pwm);
-	else
-		pwm_enable(led_dat->pwm);
 }
 
 static void led_pwm_work(struct work_struct *work)
@@ -93,6 +88,7 @@ static void led_pwm_cleanup(struct led_pwm_priv *priv)
 		led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
 		if (priv->leds[priv->num_leds].can_sleep)
 			cancel_work_sync(&priv->leds[priv->num_leds].work);
+		pwm_disable(priv->leds[i].pwm);
 	}
 }
 
@@ -132,6 +128,10 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
 	if (!led_data->period && (led->pwm_period_ns > 0))
 		led_data->period = led->pwm_period_ns;
 
+	pwm_config(led_data->pwm, led_data->active_low ? led_data->period: 0,
+		   led_data->period);
+	pwm_enable(led_data->pwm);
+
 	ret = led_classdev_register(dev, &led_data->cdev);
 	if (ret == 0) {
 		priv->num_leds++;
-- 
2.1.4