Re: [PATCH RFC] dt-bindings: thunderbolt: Add Qualcomm USB4 Host Router

[Mika Westerberg]

On Thu, Sep 18, 2025 at 05:38:13PM +0200, Konrad Dybcio wrote:
> On 9/18/25 5:23 PM, Mika Westerberg wrote:
> > Hi,
> > 
> > On Thu, Sep 18, 2025 at 11:05:42AM +0200, Konrad Dybcio wrote:
> >>> I it hard to change these DT bindings later on? If yes then I would
> >>> definitely think forward and make this support MSI from the get-go.
> >>
> >> dt-bindings (attempt to) promise an ABI-like interface, so bindings
> >> for *a given IP block* ("dt-bindings describe the hardware") should
> >> not change, unless there's something critically wrong (e.g. "this
> >> could have never really worked").
> > 
> > Then I think it is good to think few steps forward and make sure when
> > Qualcomm adds MSI to their IP it can be easily desribed in the DT bindings.
> 
> Your reply makes me believe I glossed over an important detail..
> 
> If qcom,x1e80100-hr doesn't have MSIs, qcom,nextsoc-hr can add them
> without any issues too, just that the X1E80100 binding can't be altered,
> e.g. "binding" refers to the (compatible, allowed_props, required_props)
> tuple

OK then it is all good and allows extension in the future generations.