Re: [PATCH net-next v12 2/4] net: dsa: tag_ks8995: Add the KS8995 tag handling

[Nicolai Buchwitz <nb@tipi-net.de>]

Hi Linus

On 11.9.2026 11:09, Linus Walleij wrote:
> The KS8995 100Mbit switch can do proper DSA per-port tagging
> with the proper set-up. This adds the code to handle ingress
> and egress KS8995 tags.
> 
> The tagger is used by the KSZ8995XA support added later in this
> series.
> 
> The tag is a modified 0x8100 ethertype tag where a bit in the
> last nybble is set for each target port.

Nordic nit: nybble -> nibble

> 
> Always insert a distinct outer switch tag. User ports remove this
> field on egress, so reusing an existing 802.1Q header would consume
> the sender VLAN tag instead of preserving it.
> 
> Push any hardware-accelerated VLAN tag into the packet first. This
> keeps the switch tag at offset 12 while retaining 802.1Q, 802.1ad and
> stacked VLAN headers as inner payload, and avoids relying on a valid
> SKB MAC header in direct transmit paths.
> 
> Rate-limit receive untagging errors so repeated failures cannot flood
> the kernel log.
> 
> Assisted-by: LLM
> Signed-off-by: Linus Walleij <linusw@kernel.org>
> ---

> [...]

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai