[PATCH v2] leds: fix brightness changing when software blinking is active

From: Stas Sergeev
Date: Thu May 14 2015 - 11:24:28 EST



The following sequence:
echo timer >/sys/class/leds/<name>/trigger
echo 1 >/sys/class/leds/<name>/brightness
should change the ON brightness for blinking.
The function led_set_brightness() was mistakenly initiating the
delayed blink stop procedure, which resulted in no blinking with
the timer trigger still active.

This patch fixes the problem by changing led_set_brightness()
to not initiate the delayed blink stop when brightness is not 0.

CC: Bryan Wu <cooloney@xxxxxxxxx>
CC: Richard Purdie <rpurdie@xxxxxxxxx>
CC: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
CC: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
CC: linux-leds@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx

Signed-off-by: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/leds/led-class.c | 5 +++++
drivers/leds/led-core.c | 5 +++--
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 795ec99..65c2c80 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -121,6 +121,11 @@ static void led_timer_function(unsigned long data)
brightness = led_get_brightness(led_cdev);
if (!brightness) {
/* Time to switch the LED on. */
+ if (led_cdev->delayed_set_value) {
+ led_cdev->blink_brightness =
+ led_cdev->delayed_set_value;
+ led_cdev->delayed_set_value = 0;
+ }
brightness = led_cdev->blink_brightness;
delay = led_cdev->blink_delay_on;
} else {
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 356e851..a90dd26 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -119,10 +119,11 @@ void led_set_brightness(struct led_classdev *led_cdev,
{
int ret = 0;

- /* delay brightness setting if need to stop soft-blink timer */
+ /* delay brightness if soft-blink is active */
if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
led_cdev->delayed_set_value = brightness;
- schedule_work(&led_cdev->set_brightness_work);
+ if (brightness == LED_OFF)
+ schedule_work(&led_cdev->set_brightness_work);
return;
}

--
1.7.9.5
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