Re: [PATCH 1/7] dt-bindings: interrupt-controller: mpm: Document power-domains property

[Marc Zyngier]

On Wed, 15 Jul 2026 07:38:59 +0100,
Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote:
> 
> On 13.07.2026 17:11, Marc Zyngier wrote:
> > On Mon, 13 Jul 2026 11:25:41 +0100,
> > Sneh Mankad <sneh.mankad@xxxxxxxxxxxxxxxx> wrote:
> >> Remove #power-domain-cells property and add power-domains property for
> >> MPM device.
> >>
> >> Signed-off-by: Sneh Mankad <sneh.mankad@xxxxxxxxxxxxxxxx>
> >> ---
> >>  .../devicetree/bindings/interrupt-controller/qcom,mpm.yaml          | 6 +++---
> >>  1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/Documentation/devicetree/bindings/interrupt-controller/qcom,mpm.yaml b/Documentation/devicetree/bindings/interrupt-controller/qcom,mpm.yaml
> >> index ebb40c48950ab3a8fc86f5708acfc33c33d68993..3f9645fbc3c20633077aaa589e5d5a43928dab51 100644
> >> --- a/Documentation/devicetree/bindings/interrupt-controller/qcom,mpm.yaml
> >> +++ b/Documentation/devicetree/bindings/interrupt-controller/qcom,mpm.yaml
> >> @@ -68,8 +68,8 @@ properties:
> >>          - description: MPM pin number
> >>          - description: GIC SPI number for the MPM pin
> >>  
> >> -  '#power-domain-cells':
> >> -    const: 0
> >> +  power-domains:
> >> +    maxItems: 1
> > What makes you think it is OK to change an existing binding in an
> > incompatible way?
> 
> 
> Ulf suggests that this has been modeled upside down in the initial
> submission:
> 
> https://lore.kernel.org/all/CAPx+jO9d1qH12mxg-n1rkbp6Xd__sdrSMeoc7CPELE+jgxRYHA@xxxxxxxxxxxxxx/

Sure. We have collectively fucked up a lot of bindings over the years,
mostly because of the lack of accurate documentation and people not
giving a damn about the correctness of these descriptions. I'm glad
that Ulf is now able to make it right.

But that is not a license to invalidate DTs retrospectively. We don't
update DTs in lockstep with the kernel (I *never* do), and something
that existed must be supported in the long run.

Properties can be deprecated, but:

- they must be kept in the binding

- drivers must still honor them if they are present in the DT

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.