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Date:   Tue, 16 Jun 2020 05:07:32 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     wu000273@umn.edu
Cc:     kjlu@umn.edu,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: vsp1: Fix a reference count leak.
Message-ID: <20200616020732.GK1629@pendragon.ideasonboard.com>
References: <20200613232357.18155-1-wu000273@umn.edu>
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Hi Qiushi,

(CC'ing Rafael and Geert)

Thank you for the patch.

On Sat, Jun 13, 2020 at 06:23:57PM -0500, wu000273@umn.edu wrote:
> From: Qiushi Wu <wu000273@umn.edu>
> 
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code, causing incorrect ref count if
> pm_runtime_put_noidle() is not called in error handling paths.
> Thus call pm_runtime_put_noidle() if pm_runtime_get_sync() fails.
> 
> Fixes: 1e6af546ee66 ("[media] v4l: vsp1: Implement runtime PM support")
> Signed-off-by: Qiushi Wu <wu000273@umn.edu>

https://lore.kernel.org/dri-devel/20200614134655.GA5960@pendragon.ideasonboard.com/

I really wonder if mass-patching all drivers is the best way forward.

> ---
>  drivers/media/platform/vsp1/vsp1_drv.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/vsp1/vsp1_drv.c b/drivers/media/platform/vsp1/vsp1_drv.c
> index c650e45bb0ad..222c9e1261a0 100644
> --- a/drivers/media/platform/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/vsp1/vsp1_drv.c
> @@ -846,8 +846,10 @@ static int vsp1_probe(struct platform_device *pdev)
>  	pm_runtime_enable(&pdev->dev);
>  
>  	ret = pm_runtime_get_sync(&pdev->dev);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&pdev->dev);
>  		goto done;
> +	}
>  
>  	vsp1->version = vsp1_read(vsp1, VI6_IP_VERSION);
>  	pm_runtime_put_sync(&pdev->dev);

-- 
Regards,

Laurent Pinchart