Re: [PATCH] led: core: Fix brightness setting when setting active_off=0

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

Hi Matthieu,

Thanks for catching this. Applied.

On 12/12/2017 11:10 AM, Matthieu CASTET wrote:
> With the current code, the following sequence won't work :
> echo timer > trigger
> 
> echo 0 >  delay_off
> * at this point we call
> ** led_delay_off_store
> ** led_blink_set
> *** stop timer
> ** led_blink_setup
> ** led_set_software_blink
> *** if !delay_on, led off
> *** if !delay_off, set led_set_brightness_nosleep <--- LED_BLINK_SW is set but timer is stop
> *** otherwise start timer/set LED_BLINK_SW flag
> 
> echo xxx > brightness
> * led_set_brightness
> ** if LED_BLINK_SW
> *** if brightness=0, led off
> *** else apply brightness if next timer <--- timer is stop, and will never apply new setting
> ** otherwise set led_set_brightness_nosleep
> 
> To fix that, when we delete the timer, we should clear LED_BLINK_SW.
> 
> Cc: linux-leds@vger.kernel.org
> Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
> ---
>  drivers/leds/led-core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
> index fd83c7f77a95..f3654fd2eaf3 100644
> --- a/drivers/leds/led-core.c
> +++ b/drivers/leds/led-core.c
> @@ -186,7 +186,7 @@ void led_blink_set(struct led_classdev *led_cdev,
>  		   unsigned long *delay_on,
>  		   unsigned long *delay_off)
>  {
> -	del_timer_sync(&led_cdev->blink_timer);
> +	led_stop_software_blink(led_cdev);
>  
>  	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
>  	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
> 

-- 
Best regards,
Jacek Anaszewski