Re: [PATCH net-next v2] net: dsa: yt921x: Add ACL support

[Qingfang Deng <qingfang.deng@linux.dev>]

On Wed, 20 May 2026 at 10:22:36 +0800, David Yang wrote:
> Enable filtering of incoming traffics. Note that custom filters are yet
> to be utilized, and thus not all flow dissectors are implemented.
> 
> Tested-by: hong son Nguyen <hongson.hn@gmail.com>
> Signed-off-by: David Yang <mmyangfl@gmail.com>
> ---
> v1: https://lore.kernel.org/r/20260514192140.3468543-1-mmyangfl@gmail.com
>   - fix issue reported by test robot

The always-false comparison is still there:

> +		if (match.mask->ip_proto) {
> +			enum yt921x_l4_type type = YT921X_L4_TYPE_OTHER;
> +
> +			if (match.mask->ip_proto == ~0)

../drivers/net/dsa/yt921x.c:1821:29: warning: result of comparison of constant -1 with expression of type 'u8' (aka 'unsigned char') is always false [-Wtautological-constant-out-of-range-compare]
 1821 |                         if (match.mask->ip_proto == ~0)
      |                             ~~~~~~~~~~~~~~~~~~~~ ^  ~~
1 warning generated.

> +				switch (match.key->ip_proto) {
> +				case IPPROTO_TCP:
> +					type = YT921X_L4_TYPE_TCP;