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

On 28/10/2026 03:04, Andrew Lunn wrote:

On Wed, Oct 28, 2026 at 01:13:12AM +0000, Caleb James DeLisle wrote:

quoted

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