From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Lunn <andrew@lunn.ch>
Subject: Re: [PATCH RESEND 1/2] gpio: mvebu: Add support for multiple PWM
 lines per GPIO chip
Date: Mon, 6 Aug 2018 05:38:02 +0200
Message-ID: <20180806033802.GA32450@lunn.ch>
References: <1533522556-55055-1-git-send-email-aditya@kobol.io>
 <1533522556-55055-2-git-send-email-aditya@kobol.io>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <linux-kernel-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <1533522556-55055-2-git-send-email-aditya@kobol.io>
Sender: linux-kernel-owner@vger.kernel.org
To: Aditya Prayoga <aditya@kobol.io>
Cc: linux-gpio@vger.kernel.org, Richard Genoud <richard.genoud@gmail.com>, Gregory CLEMENT <gregory.clement@bootlin.com>, Gauthier Provost <gauthier@kobol.io>, Alban Browaeys <alban.browaeys@gmail.com>, Thierry Reding <thierry.reding@gmail.com>, Linus Walleij <linus.walleij@linaro.org>, linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Dennis Gilmore <dennis@ausil.us>, Ralph Sennhauser <ralph.sennhauser@gmail.com>
List-Id: linux-gpio@vger.kernel.org

On Mon, Aug 06, 2018 at 10:29:15AM +0800, Aditya Prayoga wrote:

Hi Aditya

> +	item = kzalloc(sizeof(*item), GFP_KERNEL);
> +	if (!item)
> +		return -ENODEV;

ENOMEM would be better, since it is a memory allocation which is
failing.

>  
> -		ret = gpiod_direction_output(desc, 0);
> -		if (ret) {
> -			gpiochip_free_own_desc(desc);
> -			goto out;
> -		}
> +	spin_lock_irqsave(&mvpwm->lock, flags);
> +	desc = gpiochip_request_own_desc(&mvchip->chip,
> +					 pwm->hwpwm, "mvebu-pwm");
> +	if (IS_ERR(desc)) {
> +		ret = PTR_ERR(desc);
> +		goto out;
> +	}
>  
> -		mvpwm->gpiod = desc;
> +	ret = gpiod_direction_output(desc, 0);
> +	if (ret) {
> +		gpiochip_free_own_desc(desc);
> +		goto out;
>  	}
> +	item->gpiod = desc;
> +	item->device = pwm;
> +	INIT_LIST_HEAD(&item->node);
> +	list_add_tail(&item->node, &mvpwm->pwms);
>  out:
>  	spin_unlock_irqrestore(&mvpwm->lock, flags);
>  	return ret;

You don't cleanup item on the error path.

> @@ -630,12 +639,20 @@ static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
>  static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
>  {
>  	struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
> +	struct mvebu_pwm_item *item, *tmp;
>  	unsigned long flags;
>  
> -	spin_lock_irqsave(&mvpwm->lock, flags);
> -	gpiochip_free_own_desc(mvpwm->gpiod);
> -	mvpwm->gpiod = NULL;
> -	spin_unlock_irqrestore(&mvpwm->lock, flags);
> +	list_for_each_entry_safe(item, tmp, &mvpwm->pwms, node) {
> +		if (item->device == pwm) {
> +			spin_lock_irqsave(&mvpwm->lock, flags);
> +			gpiochip_free_own_desc(item->gpiod);
> +			item->gpiod = NULL;
> +			item->device = NULL;

Since you are about to free item, these two lines are pointless.

> +			list_del(&item->node);
> +			spin_unlock_irqrestore(&mvpwm->lock, flags);
> +			kfree(item);
> +		}
> +	}
>  }

   Andrew