Re: [PATCH] net: nixge: fix -Wvoid-pointer-to-enum-cast warning

[Simon Horman]

On Tue, Aug 15, 2023 at 08:50:13PM +0000, Justin Stitt wrote:
> When building with clang 18 I see the following warning:
> |       drivers/net/ethernet/ni/nixge.c:1273:12: warning: cast to smaller integer
> |               type 'enum nixge_version' from 'const void *' [-Wvoid-pointer-to-enum-cast]
> |        1273 |         version = (enum nixge_version)of_id->data;
> 
> This is due to the fact that `of_id->data` is a void* while `enum nixge_version`
> has the size of an int. This leads to truncation and possible data loss.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/1910
> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
> ---
> Note: There is likely no data loss occurring here since `enum nixge_version`
> has only a few fields which aren't nearly large enough to cause data
> loss. However, this patch still works towards the goal of enabling this
> warning for more builds by reducing noise.

This information might be better placed in the patch description,
above the scissors (---) and tags ("Link:", ...)

And, although I did make an error in this area myself as recently as
yesterday, this patch should probably be tagged as being for net-next.
It's probably not necessary to repost for this.

	Subject: [PATCH net-next] ...

The above notwithstanding,

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Tested-by: Simon Horman <horms@xxxxxxxxxx> # build-tested