quoted

+
+      Affected PHYs (as far as known) are GPY215B and GPY215C.
+    type: boolean
+
+dependencies:
+  maxlinear,use-broken-interrupts: [ interrupts ]

Btw. I'd presume that the tools will also allow interrupts-extended, but 
that
doesn't seem to be the case. Do I need some kind of anyOf here?

quoted

+
+unevaluatedProperties: false
+
+examples:
+  - |
+    ethernet {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ethernet-phy@0 {
+            reg = <0>;
+            interrupts-extended = <&intc 0>;
+            maxlinear,use-broken-interrupts;

This is never actually checked by be schema because there is nothing to
match on. If you want custom properties, then you need a compatible.

I can add an unwanted compatible here, or skip the example altogether. 
But
what puzzles me is that this schema pulls in the ethernet-phy.yaml. The 
latter
then has a custom select statement on the $nodename and even a comment:

# The dt-schema tools will generate a select statement first by using
# the compatible, and second by using the node name if any. In our
# case, the node name is the one we want to match on, while the
# compatible is optional.

Why doesn't that work?

-michael