Re: [PATCH v2 18/23] dt-bindings: thermal: armada: add reference to new bindings

Miquel Raynal
2018-07-16T14:32:26Z

Hi Rob,

> > > > > > for AP806 and CP110 compatibles. Add a reference to these files from the
> > > > > > original documentation.
> > > > > >
> > > > > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > > > > > ---
> > > > > > Documentation/devicetree/bindings/thermal/armada-thermal.txt | 5 +++++
> > > > > > 1 file changed, 5 insertions(+)
> > > > > >
> > > > > > diff --git a/Documentation/devicetree/bindings/thermal/armada-thermal.txt b/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> > > > > > index e0d013a2e66d..f3b441100890 100644
> > > > > > --- a/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> > > > > > +++ b/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> > > > > > @@ -10,6 +10,11 @@ Required properties:
> > > > > > * marvell,armada-ap806-thermal
> > > > > > * marvell,armada-cp110-thermal
> > > > >
> > > > > Really you should not be using the same compatible for both. Now you
> > > > > have 2 drivers matching to same compatibles.
> > > > >
> > > > > Can't you make this a child of the syscon without breaking the binding?
> > > >
> > > > We are talking about only 1 driver here, so I'm not sure how I should
> > > > understand your last sentence. Do you want me to add a second
> > > > compatible (for the same piece of hardware) for thermal node declared
> > > > as a child of the syscon?
> > >
> > > I don't know what I'm suggesting. Your changes look like they break
> > > compatibility to me.
> >
> > There is code in the driver to handle the legacy non-syscon-ish thermal
> > node ("armada_thermal_probe_legacy()"). An old DT with a new kernel
> > would work fine.
>
> Okay, that's good.
>
> > > What happens if you use this new binding without any kernel change?
> >
> > I suppose you mean "during the merge window"? In this case the driver
> > of the thermal IP will not probe (and spawn an error in the dmesg) with
> > ap806/cp110 IPs. As the support is pretty new for them, this is maybe
> > not a huge issue. Also, before the DT changes adding thermal zones,
> > just retrieving the temperature might be pretty useless. However, it
> > is always possible to merge the driver changes in 4.19 and the DT
> > changes in 4.20.
>
> Not the merge window, but distros (SUSE at least) want to be able to
> boot with current DTs and their distro (old) kernel. Maybe for this
> platform you don't care.

Indeed, I think we don't care that much for this platform.

Let me resend the series with the 'interrupt' reference removed as I
think it was the last thing to address.

Thanks,
Miquèl

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