Re: [PATCH] [net-next] net/mlx5e: fix ip6_dst_lookup link failure

[Jianbo Liu]

On 2/4/2026 9:00 PM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Changing mlx5 to call ip6_dst_lookup() means it now fails to link
> when IPv6 is a loadable module but ipsec support is built-in:
>
> ipsec.c:(.text+0x1061): undefined reference to `ip6_dst_lookup'
>
> Add a Kconfig dependency that removes avoids this configuration.
>
> Fixes: e35d7da8dd9e ("net/mlx5e: Use ip6_dst_lookup instead of ipv6_dst_lookup_flow for MAC init")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>   drivers/net/ethernet/mellanox/mlx5/core/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
> index 9cf394c66939..c298efe93f97 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
> @@ -154,6 +154,7 @@ config MLX5_EN_IPSEC
>   	depends on MLX5_CORE_EN
>   	depends on XFRM_OFFLOAD
>   	depends on INET_ESP_OFFLOAD || INET6_ESP_OFFLOAD
> +	depends on IPV6!=m || MLX5_CORE=m

Thanks for the fix.
I received a report for this same error here: 
https://lore.kernel.org/oe-kbuild-all/202512261850.P5Jp5BSz-lkp@xxxxxxxxx/

We were about to send a fix ourselves, it is to simply add:
  depends on IPV6 || !IPV6
Is there a specific reason to prefer "depends on IPV6!=m || 
MLX5_CORE=m"? To me, the IPV6 || !IPV6 syntax seems a bit cleaner.

Thanks!
Jianbo

>   	help
>   	  Build support for IPsec cryptography-offload acceleration in the NIC.
>