On 12/09/2025 10:27, Chen-Yu Tsai wrote:

quoted

quoted

+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - mediatek,mt8173-mdp-rdma
+          - mediatek,mt8173-mdp-rsz
+          - mediatek,mt8173-mdp-wdma
+          - mediatek,mt8173-mdp-wrot

Why there is no mediatek,mt8173-mdp here? What does this compatible
represent?

quoted

+      - items:
+          - const: mediatek,mt8173-mdp-rdma

Still suspicious. Device cannot be simulatanously: compatible and not
compatible. This is not a well known cat that has superposition of two
states, whenenver you look the other way.

Maybe the old binding was incorrect, maybe the in-tree DTS is incorrect.
Whichever the reason, this must be investigated and documented, because
by standard rules this is wrong. Each wrong code needs very clear
explanations (and "someone did it" is not a good enough explanation).

My guess is that "mediatek,mt8173-mdp" is meant to serve as a single
entry point for the implementation to bind the driver to. The MDP is

I am speaking about hardware. What piece of hardware it implements and
why sometimes it is RDMA MDP and sometimes it is not RDMA MDP, but only MDP.

a Data Pipeline and there could be multiple instances of the same
IP block, as seen in the original example.

The datasheet I have doesn't cover the "RDMA" block specifically, so
I can't say whether there is an actual difference between the two RDMA
blocks.

Best regards,
Krzysztof