Re: [PATCH v2] dt-bindings: interrupt-controller: loongson,liointc: Fix warnings about liointc-2.0

[Marc Zyngier]

On Wed, 30 Aug 2023 16:25:48 +0100,
Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote:
> 
> 
> 
> 在 2023/8/30 21:44, Marc Zyngier 写道:
> [...]
> >> What's the best way, in your opinion, to overhaul this property? As we don't
> >> really care backward compatibility of DTBs on those systems we can
> >> just redesign it.
> > You may not care about backward compatibility, but I do. We don't
> > break existing systems, full stop.
> Ah it won't break any existing system. Sorry for not giving enough insight
> into the platform in previous reply. As for Loongson64 all DTBs are built
> into kernel binary. So as long as binding are changed together with all DTS
> in tree we won't break any system.

This is factually wrong. QEMU produces a DT for Loongarch at runtime.
So no, you're not allowed to just drop bindings on the floor. They
stay forever.

> > As for the offending property, it has no place here either. DT is not
> > the place where you put "performance knobs".
> Hmm, I can see various bindings with vendor prefix exposing device
> configurations. If we seen this interrupt routing as a device configuration
> I don't think it's against devicetree design philosophy.

Just because we have tons of crap in the device trees doesn't give you
a license to be just as bad.

	M.

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