linux-kernel - Re: [PATCH] mtd: plat-ram: use release_mem_region instead of release

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Date:   Tue, 15 Aug 2017 11:01:59 +0200
From:   Boris Brezillon <boris.brezillon@...e-electrons.com>
To:     Anton Vasilyev <vasilyev@...ras.ru>
Cc:     David Woodhouse <dwmw2@...radead.org>,
        ldv-project@...uxtesting.org, Richard Weinberger <richard@....at>,
        linux-kernel@...r.kernel.org, Marek Vasut <marek.vasut@...il.com>,
        linux-mtd@...ts.infradead.org,
        Cyrille Pitchen <cyrille.pitchen@...ev4u.fr>,
        Brian Norris <computersforpeace@...il.com>
Subject: Re: [PATCH] mtd: plat-ram: use release_mem_region instead of
 release_resource

Le Fri, 11 Aug 2017 15:55:03 +0300,
Anton Vasilyev <vasilyev@...ras.ru> a écrit :

> Use api pair of request_mem_region and release_mem_region
> instead of release_resource.
> 
> Found by Linux Driver Verification project (linuxtesting.
> 
> Signed-off-by: Anton Vasilyev <vasilyev@...ras.ru>
> ---
>  drivers/mtd/maps/plat-ram.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mtd/maps/plat-ram.c b/drivers/mtd/maps/plat-ram.c
> index 5157289..baaf146 100644
> --- a/drivers/mtd/maps/plat-ram.c
> +++ b/drivers/mtd/maps/plat-ram.c
> @@ -82,6 +82,7 @@ static inline void platram_setrw(struct platram_info *info, int to)
>  static int platram_remove(struct platform_device *pdev)
>  {
>  	struct platram_info *info = to_platram_info(pdev);
> +	resource_size_t res_size;
>  
>  	dev_dbg(&pdev->dev, "removing device\n");
>  
> @@ -100,8 +101,8 @@ static int platram_remove(struct platform_device *pdev)
>  	/* release resources */
>  
>  	if (info->area) {
> -		release_resource(info->area);
> -		kfree(info->area);
> +		res_size = resource_size(info->area)

Missing semi-colon here, which means you did not even compile-test your
changes :P.

> +		release_mem_region(info->area->start, res_size);

Why adding a res_size variable instead of doing

		release_mem_region(info->area->start,
				   resource_size(info->area);

?

>  	}
>  
>  	if (info->map.virt != NULL)