Subject: Re: [net-next: PATCH 09/12] Documentation: ACPI: DSD: introduce DSA description

From: Andrew Lunn <[email-masked]>
Date: Wed, 22 Jun 2022 11:24:07 +0200

On Wed, Jun 22, 2022 at 11:08:13AM +0200, Marcin Wojtas wrote:
> wt., 21 cze 2022 o 13:42 Andy Shevchenko
> <[email-masked]> napisał(a):
> >
> > On Tue, Jun 21, 2022 at 01:18:38PM +0200, Andrew Lunn wrote:
> > > 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.
> >
> > I see what you mean. Honestly I dunno what the device this description is for.
> > For the DSA that's behind MDIO bus? Then it's definitely makes no sense and
> > MDIOSerialBus() resources type is what would be good to have in ACPI
> > specification.
> >
> 
> It's not device on MDIO bus, but the MDIO controller's register itself

Ah. So this is equivalent to

                CP11X_LABEL(mdio): mdio@12a200 {
                        #address-cells = <1>;
                        #size-cells = <0>;
                        compatible = "marvell,orion-mdio";
                        reg = <0x12a200 0x10>;
                        clocks = <&CP11X_LABEL(clk) 1 9>, <&CP11X_LABEL(clk) 1 5>,
                                 <&CP11X_LABEL(clk) 1 6>, <&CP11X_LABEL(clk) 1 18>;
                        status = "disabled";
                };

DT seems a lot more readable, "marvell,orion-mdio" is a good hint that
device this is. But maybe it is more readable because that is what i'm
used to.

Please could you add a lot more comments. Given that nobody currently
actually does networking via ACPI, we have to assume everybody trying
to use it is a newbie, and more comments are better than less.

Thanks
	Andrew