Re: [PATCH] leds: triggers: Check return value of kobject_uevent_env()

[Greg KH]

On Mon, Sep 19, 2016 at 10:22:51AM +0200, Jacek Anaszewski wrote:
> From: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
> 
> Log error message if kobject_uevent_env() fails in led_trigger_set().
> 
> Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> ---
>  drivers/leds/led-triggers.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> index c7a38d4..f538e8c 100644
> --- a/drivers/leds/led-triggers.c
> +++ b/drivers/leds/led-triggers.c
> @@ -141,7 +141,8 @@ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
>  	if (event) {
>  		envp[0] = event;
>  		envp[1] = NULL;
> -		kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
> +		if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
> +			pr_err("Error sending uevent after setting LED trigger\n");

You have a device, please use dev_err() for stuff like this, so that you
know what exact device caused the problem.

thanks,

greg k-h