Re: [PATCH] power: reset: at91-reset: free resources on exit path

From: Nicolas Ferre <nicolas.ferre@microchip.com>
To: Claudiu Beznea <claudiu.beznea@microchip.com>, <sre@kernel.org>,
	<alexandre.belloni@bootlin.com>,
	<ludovic.desroches@microchip.com>
Cc: <linux-pm@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, kernel test robot <lkp@intel.com>,
	"Dan Carpenter" <dan.carpenter@oracle.com>
Subject: Re: [PATCH] power: reset: at91-reset: free resources on exit path
Date: Wed, 31 Mar 2021 10:18:41 +0200	[thread overview]
Message-ID: <b18fc346-498d-4c6f-7f06-a6148a17d216@microchip.com> (raw)
In-Reply-To: <20210209110109.906034-1-claudiu.beznea@microchip.com>

On 09/02/2021 at 12:01, Claudiu Beznea wrote:
> Free resources on exit path (failure path of probe and remove).

I'm not sure we can use this driver as a module anyway.

Otherwise, it looks fine, but isn't it possible to use devm_of_iomap(), 
even in loop, and avoid having to deal with exit path?

> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>   drivers/power/reset/at91-reset.c | 25 ++++++++++++++++++++-----
>   1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
> index 3ff9d93a5226..2ff7833153b6 100644
> --- a/drivers/power/reset/at91-reset.c
> +++ b/drivers/power/reset/at91-reset.c
> @@ -206,7 +206,8 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   			if (!reset->ramc_base[idx]) {
>   				dev_err(&pdev->dev, "Could not map ram controller address\n");
>   				of_node_put(np);
> -				return -ENODEV;
> +				ret = -ENODEV;
> +				goto unmap;
>   			}
>   			idx++;
>   		}
> @@ -218,13 +219,15 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	reset->args = (u32)match->data;
>   
>   	reset->sclk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(reset->sclk))
> -		return PTR_ERR(reset->sclk);
> +	if (IS_ERR(reset->sclk)) {
> +		ret = PTR_ERR(reset->sclk);
> +		goto unmap;
> +	}
>   
>   	ret = clk_prepare_enable(reset->sclk);
>   	if (ret) {
>   		dev_err(&pdev->dev, "Could not enable slow clock\n");
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	platform_set_drvdata(pdev, reset);
> @@ -239,21 +242,33 @@ static int __init at91_reset_probe(struct platform_device *pdev)
>   	ret = register_restart_handler(&reset->nb);
>   	if (ret) {
>   		clk_disable_unprepare(reset->sclk);
> -		return ret;
> +		goto unmap;
>   	}
>   
>   	at91_reset_status(pdev, reset->rstc_base);
>   
>   	return 0;
> +
> +unmap:
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

But if we keep this loop, I have the feeling that some kind of 
"of_node_put()" is needed as well.

> +
> +	return ret;
>   }
>   
>   static int __exit at91_reset_remove(struct platform_device *pdev)
>   {
>   	struct at91_reset *reset = platform_get_drvdata(pdev);
> +	int idx;
>   
>   	unregister_restart_handler(&reset->nb);
>   	clk_disable_unprepare(reset->sclk);
>   
> +	iounmap(reset->rstc_base);
> +	for (idx = 0; idx < ARRAY_SIZE(reset->ramc_base); idx++)
> +		iounmap(reset->ramc_base[idx]);

Ditto

> +
>   	return 0;
>   }
>   
> 

-- 
Nicolas Ferre