Re: [PATCH V3 11/21] pci, acpi: Move ACPI host bridge device companion assignment to core code.

[Tomasz Nowicki]

On 20.01.2016 15:22, Lorenzo Pieralisi wrote:
> On Wed, Jan 20, 2016 at 02:40:08PM +0100, Tomasz Nowicki wrote:
>
> [...]
>
> > > > > > +	/* Root bridge device needs to be sure of parent ACPI type */
> > > > > > +	ACPI_COMPANION_SET(&device->dev, device);
> > > > >
> > > > > I do not understand why the code above is needed, can you elaborate
> > > > > please ?
> > > >
> > > > This makes sure that device->dev can be identified as ACPI device,
> > > > so we can use to_acpi_device_node() and assign companion safely
> > > > below.
> > >
> > > I do not follow. If you refer to the fwnode handle type, that is
> > > already set by ACPI core code (before acpi_pci_root_add() is called,
> > > in acpi_init_device_object()).
> >
> > acpi_init_device_object() sets ACPI fwnode handle type only for
> > "device", but not for "device->dev" which is what is passed as an
> > argument to pci_create_root_bus().
> >
> > Without ACPI_COMPANION_SET(&device->dev, device) here, no one can be
> > sure if we have ACPI device in pci_create_root_bus().
>
> Ok, got it. The question is whether this should be done in ACPI
> core instead (is there a reason why it should *not* be done ?), but I
> now understand your point.

I am not able to answer that question, but I see lots of changes in this 
area made by Rafael.

Rafael, can you please shed some light on this?

Thanks,
Tomasz