linux-kernel - Re: [PATCH 4/4] extcon: extcon-max8997: Fix IRQ freeing at error path

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Message-ID: <edf3ff4d-8bd7-17cf-0d7c-96b4f704dddd@canonical.com>
Date:   Mon, 10 May 2021 10:21:41 -0400
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
        Matti Vaittinen <mazziesaccount@...il.com>
Cc:     Chanwoo Choi <cw00.choi@...sung.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] extcon: extcon-max8997: Fix IRQ freeing at error path

On 10/05/2021 04:12, Matti Vaittinen wrote:
> If reading MAX8997_MUIC_REG_STATUS1 fails at probe the driver exits
> without freeing the requested IRQs.

The driver frees IRQ on probe failure, so maybe you meant missing IRQ
mapping dispose?

> 
> Simplify driver and fix the IRQ problem by switching to use the
> resource managed IRQ requesting and resource managed work-queue
> initialization.
> 
> Fixes: 3e34c8198960 ("extcon: max8997: Avoid forcing UART path on drive probe")
> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
> ---
> 
> Please note that the change is compile-tested only. All proper testing is
> highly appreciated.
> ---
>  drivers/extcon/extcon-max8997.c | 45 +++++++++++----------------------
>  1 file changed, 15 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/extcon/extcon-max8997.c b/drivers/extcon/extcon-max8997.c
> index e1408075ef7d..bbc592823570 100644
> --- a/drivers/extcon/extcon-max8997.c
> +++ b/drivers/extcon/extcon-max8997.c
> @@ -5,6 +5,7 @@
>  //  Copyright (C) 2012 Samsung Electronics
>  //  Donggeun Kim <dg77.kim@...sung.com>
>  
> +#include <linux/devm-helpers.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/i2c.h>
> @@ -650,27 +651,30 @@ static int max8997_muic_probe(struct platform_device *pdev)
>  	mutex_init(&info->mutex);
>  
>  	INIT_WORK(&info->irq_work, max8997_muic_irq_work);
> +	ret = devm_work_autocancel(&pdev->dev, &info->irq_work,
> +				   max8997_muic_irq_work);
> +	if (ret)
> +		return ret;
>  
>  	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
>  		struct max8997_muic_irq *muic_irq = &muic_irqs[i];
>  		unsigned int virq = 0;
>  
>  		virq = irq_create_mapping(max8997->irq_domain, muic_irq->irq);
> -		if (!virq) {
> -			ret = -EINVAL;
> -			goto err_irq;
> -		}
> +		if (!virq)
> +			return -EINVAL;
> +
>  		muic_irq->virq = virq;
>  
> -		ret = request_threaded_irq(virq, NULL,
> -				max8997_muic_irq_handler,
> -				IRQF_NO_SUSPEND,
> -				muic_irq->name, info);
> +		ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
> +						max8997_muic_irq_handler,
> +						IRQF_NO_SUSPEND,
> +						muic_irq->name, info);
>  		if (ret) {
>  			dev_err(&pdev->dev,
>  				"failed: irq request (IRQ: %d, error :%d)\n",
>  				muic_irq->irq, ret);
> -			goto err_irq;
> +			return ret;
>  		}
>  	}
>  
> @@ -678,14 +682,13 @@ static int max8997_muic_probe(struct platform_device *pdev)
>  	info->edev = devm_extcon_dev_allocate(&pdev->dev, max8997_extcon_cable);
>  	if (IS_ERR(info->edev)) {
>  		dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
> -		ret = PTR_ERR(info->edev);
> -		goto err_irq;
> +		return PTR_ERR(info->edev);
>  	}
>  
>  	ret = devm_extcon_dev_register(&pdev->dev, info->edev);
>  	if (ret) {
>  		dev_err(&pdev->dev, "failed to register extcon device\n");
> -		goto err_irq;
> +		return ret;
>  	}
>  
>  	if (pdata && pdata->muic_pdata) {
> @@ -756,23 +759,6 @@ static int max8997_muic_probe(struct platform_device *pdev)
>  			delay_jiffies);
>  
>  	return 0;
> -
> -err_irq:
> -	while (--i >= 0)
> -		free_irq(muic_irqs[i].virq, info);

Here it will unwind what was done.

> -	return ret;
> -}
> -


Best regards,
Krzysztof