[PATCH 2/2] leds/pwm: Don't disable pwm when setting brightness to 0
From: Uwe Kleine-König <hidden>
Date: 2015-02-12 09:44:50
Also in:
linux-leds, linux-pwm
Subsystem:
led subsystem, the rest · Maintainers:
Lee Jones, Pavel Machek, Linus Torvalds
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-K?nig <redacted> --- 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