Re: [PATCH net-next v25 06/10] net: dsa: tag_mtk: add Airoha variant usage of this TAG

[Christian Marangi <ansuelsmth@gmail.com>]

On Sat, Oct 10, 2026 at 04:11:37PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] net: dsa: airoha/mtk eth: hardware offload broken for AIROHA tag protocol
> --
> 
> commit feed6f0245d293aabba2178225f4097258a1d66c
> Author: Christian Marangi <ansuelsmth@gmail.com>
> 
> net: dsa: tag_mtk: add Airoha variant usage of this TAG
> 
> This commit adds a new DSA tag protocol variant for Airoha switches,
> updating the Mediatek tag driver, Kconfig, and Makefile. It also adds
> comments explaining the differences between Airoha AN8855 and the Mediatek
> tag bitmap.
> 
> > diff --git a/include/net/dsa.h b/include/net/dsa.h
> > index 5d12191b6f6f5..9824c63ad50b3 100644
> > --- a/include/net/dsa.h
> > +++ b/include/net/dsa.h
> [ ... ]
> > @@ -76,6 +77,7 @@ enum dsa_tag_protocol {
> >  	DSA_TAG_PROTO_KSZ9893		= DSA_TAG_PROTO_KSZ9893_VALUE,
> >  	DSA_TAG_PROTO_LAN9303		= DSA_TAG_PROTO_LAN9303_VALUE,
> >  	DSA_TAG_PROTO_MTK		= DSA_TAG_PROTO_MTK_VALUE,
> > +	DSA_TAG_PROTO_AIROHA		= DSA_TAG_PROTO_AIROHA_VALUE,
> 
> [Severity: High]
> Does adding this new protocol ID require updating the ethernet MAC and PPE
> drivers to recognize it as well?
> 
> For example, looking at airoha_get_dsa_tag() in
> drivers/net/ethernet/airoha/airoha_eth.c:
> 
> 	if (dev->dsa_ptr->tag_ops->proto != DSA_TAG_PROTO_MTK)
> 		return 0;
> 
> And mtk_uses_dsa() in drivers/net/ethernet/mediatek/mtk_eth_soc.c:
> 
> 	return netdev_uses_dsa(dev) &&
> 	       dev->dsa_ptr->tag_ops->proto == DSA_TAG_PROTO_MTK;
> 
> If these are not updated to also accept DSA_TAG_PROTO_AIROHA, will hardware
> tag extraction and PPE hardware flow offloading (like in __mtk_ppe_check_skb()
> and mtk_flow_get_dsa_port()) fail because the strict protocol checks against
> DSA_TAG_PROTO_MTK no longer match?
>

This is irrelevant for this series and can be handled later. I'm not sure
offload can work with the AN8855 external switch.
 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/20261009161102.38961-1-ansuelsmth@gmail.com?part=6

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