Re: [PATCH RFC v1 net-next] net: ethernet: mtk_ppe_offload: Allow QinQ

From: Eric Woudstra
Date: Tue Oct 15 2024 - 11:25:50 EST




On 10/14/24 10:51 AM, Simon Horman wrote:
> On Sun, Oct 13, 2024 at 08:50:56PM +0200, Eric Woudstra wrote:
>> mtk_foe_entry_set_vlan() in mtk_ppe.c already seems to support
>> double vlan tagging, but mtk_flow_offload_replace() in
>> mtk_ppe_offload.c only allows for 1 vlan tag, optionally in
>> combination with pppoe and dsa tags.
>>
>> This patch adds QinQ support to mtk_flow_offload_replace().
>>
>> Only PPPoE-in-Q (as before) and Q-in-Q are allowed. A combination
>> of PPPoE and Q-in-Q is not allowed.
>>
>> As I do not have any documentation of the ppe hardware, I do not
>> know if there is any other reason to not implement Q-in-Q in
>> mtk_flow_offload_replace().
>>
>> Tested on the BPI-R3(mini), on non-dsa-ports and dsa-ports.
>>
>> Signed-off-by: Eric Woudstra <ericwouds@xxxxxxxxx>
>
> Hi Eric,
>
> I see that this patch supports up to two VLANs, both with EtherType 0x8100.
> And assuming that is supported by the hardware, that seems fine to me.
>
> But I winder if you know if this hardware supports other VLAN EtherTypes,
> such as 0x88a8 which is described in 802.1ad?

Hello Simon,

The issue is that I do not have the documentation. Therefore I submit
this patch as RFC and I hope someone at mediatek or so can confirm we can
implement QinQ as in this patch on all hardware that uses mtk_ppe_offload.

But it does not look like it supports 0x88a8 from 802.1ad.