Re: [PATCH v13 07/10] firmware: psci: Implement vendor-specific resets as reboot-mode

[Dmitry Baryshkov]

On 28/07/2025 14:52, Krzysztof Kozlowski wrote:
> On 28/07/2025 11:44, Dmitry Baryshkov wrote:
> > On Mon, Jul 28, 2025 at 06:53:14AM +0200, Krzysztof Kozlowski wrote:
> > > On 27/07/2025 18:24, Shivendra Pratap wrote:
> > > > +
> > > > +static int __init psci_init_vendor_reset(void)
> > > > +{
> > > > +	struct reboot_mode_driver *reboot;
> > > > +	struct device_node *np;
> > > > +	int ret;
> > > > +
> > > > +	np = of_find_node_by_path("/psci/reboot-mode");
> > >
> > >
> > > Why are you looking by full path, not by compatible? Is the ABI - above
> > > path - expressed anywhere?
> >
> > PSCI node is required to have a node name of psci, it doesn't have MMIO,
>
> This is true
>
> > so it resides in the root node
>
> This might be or not might be true. It is not defined by ABI. Anyway,
> you answered where the ABI would be documented, even though as I said it
> is not (/psci is not), but does not answer to first part: why you are
> not using compatibles which is always the preferred method?

That's a good question, I've added one from my side: why do we need an 
extra late_init call.

> > and the reboot-mode is defined in the
> > previous patch. So, I'd assume, the path is defined.
>
> As I said, path is not. only psci/reboot-mode is.

Do we have an _actual_ use case where PSCI node is not at at root node? 
If not, it's obviously a deficiency of the schema. Could you please 
provide suggestions on how to describe that in DT schema?


--
With best wishes
Dmitry