Re: [PATCH] leds: core: use deferred probing if default trigger isn't available yet

[Pavel Machek <pavel@ucw.cz>]

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On Wed 2017-02-22 21:35:52, Heiner Kallweit wrote:
> When registering a LED device we have the option to set a default trigger.
> Depending on load order of drivers this trigger may not be available yet.
> (affected LED device in my case: a DT-configured GPIO LED)
> So far if the default trigger can't be found this error is silently
> ignored.
> 
> Let's change this to return EPROBE_DEFER if the default trigger can't be
> found. This gives the system the chance to probe the LED device later
> once the trigger is available.

I see a lot of EPROBE_DEFERs on N900, and it is quite nasty, as it
spams a log a lot.

Rather then re-trying LED registration few times, could we make sure
leds are always registered after triggers or something like that?

     	 		   	 	     	       	    Pavel


> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
> ---
>  drivers/leds/led-class.c    |  6 +++++-
>  drivers/leds/led-triggers.c | 11 ++++++++---
>  include/linux/leds.h        |  5 +++--
>  3 files changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index f2b0a80a..efe4f5a3 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -295,7 +295,11 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
>  	led_init_core(led_cdev);
>  
>  #ifdef CONFIG_LEDS_TRIGGERS
> -	led_trigger_set_default(led_cdev);
> +	ret = led_trigger_set_default(led_cdev);
> +	if (ret) {
> +		led_classdev_unregister(led_cdev);
> +		return ret;
> +	}

-- 
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