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Date:   Tue, 21 Jun 2022 13:18:38 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Marcin Wojtas <mw@semihalf.com>, linux-kernel@vger.kernel.org,
        linux-acpi@vger.kernel.org, netdev@vger.kernel.org,
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        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        linux@armlinux.org.uk, hkallweit1@gmail.com, gjb@semihalf.com,
        jaz@semihalf.com, tn@semihalf.com, Samer.El-Haj-Mahmoud@arm.com,
        upstream@semihalf.com
Subject: Re: [net-next: PATCH 09/12] Documentation: ACPI: DSD: introduce DSA
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On Tue, Jun 21, 2022 at 02:09:14PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 20, 2022 at 09:47:31PM +0200, Andrew Lunn wrote:
> 
> ...
> 
> > > +        Name (_CRS, ResourceTemplate ()
> > > +        {
> > > +            Memory32Fixed (ReadWrite,
> > > +                0xf212a200,
> > > +                0x00000010,
> > 
> > What do these magic numbers mean?
> 
> Address + Length, it's all described in the ACPI specification.

The address+plus length of what? This device is on an MDIO bus. As
such, there is no memory! It probably makes sense to somebody who
knows ACPI, but to me i have no idea what it means.

> Or if you asked
> why the values there are the particular numbers? I guess it's fined to have
> anything sane in the example. OTOH a comment may be added.
> 
> > > +                )
> > > +        })
> 
> ...
> 
> > > +        Device (SWI0)
> > > +        {
> > > +            Name (_HID, "MRVL0120")
> > > +            Name (_UID, 0x00)
> > > +            Name (_ADR, 0x4)
> > > +            <...>
> > > +        }
> > 
> > I guess it is not normal for ACPI, but could you add some comments
> > which explain this. In DT we have
> > 
> >     properties:
> >       reg:
> >         minimum: 0
> >         maximum: 31
> >         description:
> >           The ID number for the device.
> > 
> > which i guess what this _ADR property is, but it would be nice if it
> > actually described what it is supposed to mean. You have a lot of
> > undocumented properties here.
> 
> Btw, you are right, _ADR mustn't go together with _HID/_CID.

Does ACPI have anything like .yaml to describe the binding and tools
to validate it?

   Andrew