Re: [PATCH v3 2/7] dt-bindings: net: dsa: mediatek,mt7530: add passthrough mode

[Caleb James DeLisle <cjd@cjdns.fr>]

On 28/10/2026 03:04, Andrew Lunn wrote:
> On Wed, Oct 28, 2026 at 01:13:12AM +0000, Caleb James DeLisle wrote:
>> MT7530 switches can be configured to blindly pass packets between their
>> CPU/upstream port and a downstream DSA port, in particular, without
>> altering the MediaTek DSA Tag on the packets. This mode is used in some
>> integrations where an SoC integrated switch exists, but a more capable
>> MCM switch is added to effectively replace it.
>>
>> Signed-off-by: Caleb James DeLisle <cjd@cjdns.fr>
>> Acked-by: Rob Herring (Arm) <robh@kernel.org>
>> ---
>>   .../devicetree/bindings/net/dsa/mediatek,mt7530.yaml       | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> index 90b3582b7619..e29fb8693498 100644
>> --- a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> +++ b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> @@ -73,6 +73,13 @@ description: |
>>   
>>         Check out example 7.
>>   
>> +  The MT7530 and MT7531 switches are capable of being operated in "passthrough"
>> +  mode. In this mode, traffic is unconditionally passed between the CPU port
>> +  and the DSA port which links to a second switch. To use passthrough mode, the
>> +  upstream switch is configured with a DSA link to the downstream switch. In
>> +  passthrough mode the upstream switch is restricted, with no other ports or
>> +  switch configuration allowed.
>> +
>>   properties:
>>     compatible:
>>       oneOf:
> Looking at just what is here, all i see is a comment. There is no new
> property? Yet the subject is "add passthrough mode"?


Indeed, I used "add" to mean "add documentation of". Per my reply on 
patch 3, I think we really prefer to avoid special properties and let 
this constitute (very) limited support for a switch hierarchy.

If there's another verb you think makes a better commit line, I'd be 
happy to adjust.


Thanks,

Caleb


>
> 	Andrew