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Date:   Fri, 6 Jan 2023 15:37:28 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Miaoqian Lin <linmq006@gmail.com>
Cc:     Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: platform: Fix refcount leak in probe and remove
 function
Message-ID: <Y7gkGGEFDQShRr5o@pendragon.ideasonboard.com>
References: <20230106075809.966856-1-linmq006@gmail.com>
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In-Reply-To: <20230106075809.966856-1-linmq006@gmail.com>
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Hello Miaoqian,

Thank you for the patch.

On Fri, Jan 06, 2023 at 11:58:09AM +0400, Miaoqian Lin wrote:
> rcar_fcp_get() take reference, which should be balanced with
> rcar_fcp_put(). Add missing rcar_fcp_put() in fdp1_remove and
> the error paths of fdp1_probe() to fix this.
> 
> Fixes: 4710b752e029 ("[media] v4l: Add Renesas R-Car FDP1 Driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> I take commit Fixes: 7113469dafc2 ("media: vsp1: Fix an error handling
> path in the probe function") for reference.
> ---
>  drivers/media/platform/renesas/rcar_fdp1.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar_fdp1.c b/drivers/media/platform/renesas/rcar_fdp1.c
> index 37ecf489d112..ed97bb161743 100644
> --- a/drivers/media/platform/renesas/rcar_fdp1.c
> +++ b/drivers/media/platform/renesas/rcar_fdp1.c
> @@ -2313,8 +2313,10 @@ static int fdp1_probe(struct platform_device *pdev)
>  
>  	/* Determine our clock rate */
>  	clk = clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(clk))
> -		return PTR_ERR(clk);
> +	if (IS_ERR(clk)) {
> +		ret = PTR_ERR(clk);
> +		goto put_dev;
> +	}
>  
>  	fdp1->clk_rate = clk_get_rate(clk);
>  	clk_put(clk);
> @@ -2323,7 +2325,7 @@ static int fdp1_probe(struct platform_device *pdev)
>  	ret = v4l2_device_register(&pdev->dev, &fdp1->v4l2_dev);
>  	if (ret) {
>  		v4l2_err(&fdp1->v4l2_dev, "Failed to register video device\n");
> -		return ret;
> +		goto put_dev;
>  	}
>  
>  	/* M2M registration */
> @@ -2393,6 +2395,8 @@ static int fdp1_probe(struct platform_device *pdev)
>  unreg_dev:
>  	v4l2_device_unregister(&fdp1->v4l2_dev);
>  
> +put_dev:
> +	rcar_fcp_put(fdp1->fcp);
>  	return ret;
>  }
>  
> @@ -2400,6 +2404,7 @@ static int fdp1_remove(struct platform_device *pdev)
>  {
>  	struct fdp1_dev *fdp1 = platform_get_drvdata(pdev);
>  
> +	rcar_fcp_put(fdp1->fcp);

I would move it at the end, after unregistering the V4L2 device, as here
we may still be using the fcp.

Apart from that, the patch looks good to me.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

No need to send a v2, I'll make this small change in my tree.

>  	v4l2_m2m_release(fdp1->m2m_dev);
>  	video_unregister_device(&fdp1->vfd);
>  	v4l2_device_unregister(&fdp1->v4l2_dev);

-- 
Regards,

Laurent Pinchart