linux-kernel - Re: [RFC PATCH 5/5] leds: multicolor: Introduce a multicolor class definition

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Date:   Tue, 2 Apr 2019 07:44:06 +0200
From:   Marek Behun <marek.behun@....cz>
To:     Dan Murphy <dmurphy@...com>
Cc:     <robh+dt@...nel.org>, <jacek.anaszewski@...il.com>, <pavel@....cz>,
        <linux-kernel@...r.kernel.org>, <linux-leds@...r.kernel.org>
Subject: Re: [RFC PATCH 5/5] leds: multicolor: Introduce a multicolor class
 definition

Hi Dan,

On Mon, 1 Apr 2019 12:34:00 -0500
Dan Murphy <dmurphy@...com> wrote:

> +static ssize_t sync_store(struct device *dev,
> +			  struct device_attribute *sync_attr,
> +			  const char *buf, size_t size)
> +{
> +	struct led_classdev_mc_data *data = container_of(sync_attr,
> +						      struct led_classdev_mc_data,
> +						      sync_attr);
> +	struct led_classdev_mc *mcled_cdev = data->mcled_cdev;
> +	struct led_classdev *led_cdev = &mcled_cdev->led_cdev;
> +	const struct led_multicolor_ops *ops = mcled_cdev->ops;
> +	struct led_classdev_mc_priv *priv;
> +	unsigned long sync_value;
> +	ssize_t ret = -EINVAL;
> +
> +	mutex_lock(&led_cdev->led_access);
> +
> +	if (!mcled_cdev->sync_enabled)
> +		goto unlock;

This lock is redundant, you could just put
  if (mcled_cdev->sync_enabled)
    return ret;
before the lock.