Re: [PATCH] drm/imx/dcss: fix resource size calculation

[Laurentiu Palcu]

Hi Dan,

On Tue, Feb 13, 2024 at 09:05:01PM +0300, Dan Carpenter wrote:
> The resource is inclusive of the ->start and ->end addresses so this
> calculation is not correct.  It should be "res->end - res->start + 1".
> Use the resource_size() to do the calculation.
> 
> Fixes: 90393c9b5408 ("drm/imx/dcss: request memory region")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Reviewed-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx>

And pushed to drm-misc-next-fixes.

Thanks,
Laurentiu

> ---
> From static analysis.  Not tested.
> 
>  drivers/gpu/drm/imx/dcss/dcss-dev.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/imx/dcss/dcss-dev.c b/drivers/gpu/drm/imx/dcss/dcss-dev.c
> index 597e9b7bd4bf..7fd0c4c14205 100644
> --- a/drivers/gpu/drm/imx/dcss/dcss-dev.c
> +++ b/drivers/gpu/drm/imx/dcss/dcss-dev.c
> @@ -167,7 +167,6 @@ struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output)
>  	struct resource *res;
>  	struct dcss_dev *dcss;
>  	const struct dcss_type_data *devtype;
> -	resource_size_t res_len;
>  
>  	devtype = of_device_get_match_data(dev);
>  	if (!devtype) {
> @@ -181,8 +180,7 @@ struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output)
>  		return ERR_PTR(-EINVAL);
>  	}
>  
> -	res_len = res->end - res->start;
> -	if (!devm_request_mem_region(dev, res->start, res_len, "dcss")) {
> +	if (!devm_request_mem_region(dev, res->start, resource_size(res), "dcss")) {
>  		dev_err(dev, "cannot request memory region\n");
>  		return ERR_PTR(-EBUSY);
>  	}
> -- 
> 2.43.0
>