Re: [PATCH] IB/mlx4: Avoid implicit enumerated type conversion

[Nick Desaulniers]

On Mon, Sep 24, 2018 at 12:57 PM Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> Clang warns when one enumerated type is implicitly converted to another.
>
> drivers/infiniband/hw/mlx4/mad.c:1811:41: warning: implicit conversion
> from enumeration type 'enum mlx4_ib_qp_flags' to different enumeration
> type 'enum ib_qp_create_flags' [-Wenum-conversion]
>                 qp_init_attr.init_attr.create_flags = MLX4_IB_SRIOV_TUNNEL_QP;
>                                                     ~ ^~~~~~~~~~~~~~~~~~~~~~~
>
> drivers/infiniband/hw/mlx4/mad.c:1819:41: warning: implicit conversion
> from enumeration type 'enum mlx4_ib_qp_flags' to different enumeration
> type 'enum ib_qp_create_flags' [-Wenum-conversion]
>                 qp_init_attr.init_attr.create_flags = MLX4_IB_SRIOV_SQP;
>                                                     ~ ^~~~~~~~~~~~~~~~~
>
> The type mlx4_ib_qp_flags explicitly provides supplemental values to the
> type ib_qp_create_flags. Make that clear to Clang by changing the
> create_flags type to u32.
>
> Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> ---
>  include/rdma/ib_verbs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index e463d3007a35..f6f4d9e3c8ed 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -1149,7 +1149,7 @@ struct ib_qp_init_attr {
>         struct ib_qp_cap        cap;
>         enum ib_sig_type        sq_sig_type;
>         enum ib_qp_type         qp_type;
> -       enum ib_qp_create_flags create_flags;
> +       u32                     create_flags;

I think it might be better to just have explicit casts at the
assignment.  What do the maintainers think?

>
>         /*
>          * Only needed for special QP types, or when using the RW API.
> --
> 2.19.0
>


-- 
Thanks,
~Nick Desaulniers