[PATCH 4.4 42/91] leds: call led_pwm_set() in leds-pwm to enforce default LED_OFF

Greg Kroah-Hartman
2018-12-11T16:18:51Z

From: Markus Hofstaetter <markus.hofstaetter@ait.ac.at>

commit f16703360da7731a057df2ffa902306819c22398 upstream.

Some PWMs are disabled by default or the default pin setting
does not match the LED_OFF state (e.g., active-low leds).
Hence, the driver may end up reporting 0 brightness, but
the leds are actually on using full brightness, because
it never enforces its default configuration.
So enforce it by calling led_pwm_set() after successfully
registering the device.

Tested on a Phytec phyFLEX i.MX6Q board based on kernel
v3.19.5.

Signed-off-by: Markus Hofstaetter <markus.hofstaetter@ait.ac.at>
Tested-by: Markus Hofstaetter <markus.hofstaetter@ait.ac.at>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/leds/leds-pwm.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -132,6 +132,7 @@ static int led_pwm_add(struct device *de
ret = led_classdev_register(dev, &led_data->cdev);
if (ret == 0) {
priv->num_leds++;
+ led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
} else {
dev_err(dev, "failed to register PWM led for %s: %d\n",
led->name, ret);