Re: [PATCH] libnvdimm.h: Remove duplicate struct declaration

[Ira Weiny]

On Mon, Apr 19, 2021 at 07:27:25PM +0800, Wan Jiabing wrote:
> struct device is declared at 133rd line.
> The declaration here is unnecessary. Remove it.
> 
> Signed-off-by: Wan Jiabing <wanjiabing@xxxxxxxx>
> ---
>  include/linux/libnvdimm.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
> index 01f251b6e36c..89b69e645ac7 100644
> --- a/include/linux/libnvdimm.h
> +++ b/include/linux/libnvdimm.h
> @@ -141,7 +141,6 @@ static inline void __iomem *devm_nvdimm_ioremap(struct device *dev,
>  
>  struct nvdimm_bus;
>  struct module;
> -struct device;
>  struct nd_blk_region;

What is the coding style preference for pre-declarations like this?  Should
they be placed at the top of the file?

The patch is reasonable but if the intent is to declare right before use for
clarity, both devm_nvdimm_memremap() and nd_blk_region_desc() use struct
device.  So perhaps this duplicate is on purpose?

Ira

>  struct nd_blk_region_desc {
>  	int (*enable)(struct nvdimm_bus *nvdimm_bus, struct device *dev);
> -- 
> 2.25.1
>