linux-kernel - Re: [PATCH 1/2] leds: save the delay values after a successful call to blink

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Date:	Fri, 07 Oct 2011 09:38:38 +0200
From:	Johannes Berg <johannes.berg@...el.com>
To:	Antonio Ospite <ospite@...denti.unina.it>
Cc:	Richard Purdie <rpurdie@...ys.net>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] leds: save the delay values after a successful
 call to blink_set()

On Thu, 2011-10-06 at 22:03 +0000, Antonio Ospite wrote:
> When calling the hardware blinking function implemented by blink_set(),
> the delay_on and delay_off values are not preserved across calls.
> 
> Fix that and make the "timer" trigger work as expected when hardware
> blinking is available.
> 
> BEFORE the fix:
>   $ cd /sys/class/leds/someled
>   $ echo timer > trigger
>   $ cat delay_on delay_off
>   0
>   0
>   $ echo 100 > delay_on
>   $ cat delay_on delay_off
>   0
>   0
>   $ echo 100 > delay_off
>   $ cat delay_on delay_off
>   0
>   0
> 
> AFTER the fix:
>   $ cd /sys/class/leds/someled
>   $ echo timer > trigger
>   $ cat delay_on delay_off
>   0
>   0
>   $ echo 100 > delay_on
>   $ cat delay_on delay_off
>   100
>   0
>   $ echo 100 > delay_off
>   $ cat delay_on delay_off
>   100
>   100
> 
> Signed-off-by: Antonio Ospite <ospite@...denti.unina.it>
> ---
>  drivers/leds/led-class.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index d5a4ade..939f24a 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -267,8 +267,11 @@ void led_blink_set(struct led_classdev *led_cdev,
>                    unsigned long *delay_off)
>  {
>         if (led_cdev->blink_set &&
> -           !led_cdev->blink_set(led_cdev, delay_on, delay_off))
> +           !led_cdev->blink_set(led_cdev, delay_on, delay_off)) {
> +               led_cdev->blink_delay_on = *delay_on;
> +               led_cdev->blink_delay_off = *delay_off;
>                 return;
> +       }

Looks good to me. I suspect I created this bug because originally it
might have put the values into there first and then called blink_set().

Reviewed-by: Johannes Berg <johannes@...solutions.net>

johannes

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