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

From: Marcin Wojtas
Date: Wed Jun 22 2022 - 05:10:18 EST


wt., 21 cze 2022 o 13:42 Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> 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
(this _CSR belongs to the parent, subnodes do not refer to it in any
way). The child device requires only _ADR (or whatever else is needed
for the case the DSA device is attached to SPI/I2C controllers).

Best regards,
Marcin