There are valid cases when two nodes can have the same address. For example, in Exynos SoCs there is USI IP-core, which might be configured to provide UART, SPI or I2C block, all of which having the same base register address. But only one can be enabled at a time. That looks like this: usi@138200c0 { serial@13820000 { status = "okay"; }; i2c@13820000 { status = "disabled"; }; }; When running "make dt_binding_check", it reports next warning: Warning (unique_unit_address): /example-0/usi@138200c0/serial@13820000: duplicate unit-address (also used in node /example-0/usi@138200c0/i2c@13820000) Disable "unique_unit_address" in DTC_FLAGS to suppress warnings like that, but enable "unique_unit_address_if_enabled" warning, so that dtc still reports a warning when two enabled nodes are having the same address. Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx> Reported-by: Rob Herring <robh@xxxxxxxxxx> Suggested-by: Rob Herring <robh@xxxxxxxxxx> --- Documentation/devicetree/bindings/Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile index c9abfbe3f0aa..41c555181b6f 100644 --- a/Documentation/devicetree/bindings/Makefile +++ b/Documentation/devicetree/bindings/Makefile @@ -65,7 +65,9 @@ DT_DOCS = $(patsubst $(srctree)/%,%,$(shell $(find_all_cmd))) override DTC_FLAGS := \ -Wno-avoid_unnecessary_addr_size \ -Wno-graph_child_address \ - -Wno-interrupt_provider + -Wno-interrupt_provider \ + -Wno-unique_unit_address \ + -Wunique_unit_address_if_enabled # Disable undocumented compatible checks until warning free override DT_CHECKER_FLAGS ?= -- 2.30.2