On Wed, 10 May 2023, Hans de Goede wrote: > When a trigger wants to switch from blinking to LED on it needs to call: > led_set_brightness(LED_OFF); > led_set_brightness(LED_FULL); > > To first call disables blinking and the second then turns the LED on > (the power-supply charging-blink-full-solid triggers do this). > > These calls happen immediately after each other, so it is possible > that set_brightness_delayed() from the first call has not run yet > when the led_set_brightness(LED_FULL) call finishes. > > If this race hits then this is causing problems for both > sw- and hw-blinking: > > For sw-blinking set_brightness_delayed() clears delayed_set_value > when LED_BLINK_DISABLE is set causing the led_set_brightness(LED_FULL) > call effects to get lost when hitting the race, resulting in the LED > turning off instead of on. > > For hw-blinking if the race hits delayed_set_value has been > set to LED_FULL by the time set_brightness_delayed() runs. > So led_cdev->brightness_set_blocking() is never called with > LED_OFF as argument and the hw-blinking is never disabled leaving > the LED blinking instead of on. > > Fix both issues by adding LED_SET_BRIGHTNESS and LED_SET_BRIGHTNESS_OFF > work_flags making this 2 separate actions to be run by > set_brightness_delayed(). > > Reviewed-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx> > Tested-by: Yauhen Kharuzhy <jekhor@xxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/leds/led-core.c | 57 +++++++++++++++++++++++++++++++---------- > include/linux/leds.h | 3 +++ > 2 files changed, 47 insertions(+), 13 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
