On Tue, Jun 21, 2022 at 05:23:30PM +0200, Rafael J. Wysocki wrote:

On Tue, Jun 21, 2022 at 3:28 PM Sudeep Holla [off-list ref] wrote:

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On Tue, Jun 21, 2022 at 01:24:51PM +0200, Andrew Lunn wrote:

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On Tue, Jun 21, 2022 at 02:15:41PM +0300, Andy Shevchenko wrote:

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On Tue, Jun 21, 2022 at 10:45:56AM +0100, Sudeep Holla wrote:

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On Mon, Jun 20, 2022 at 05:02:22PM +0200, Marcin Wojtas wrote:

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Describe the Distributed Switch Architecture (DSA) - compliant
MDIO devices. In ACPI world they are represented as children
of the MDIO busses, which are responsible for their enumeration
based on the standard _ADR fields and description in _DSD objects
under device properties UUID [1].

[1] http://www.uefi.org/sites/default/files/resources/_DSD-device-properties-UUID.pdf

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Why is this document part of Linux code base ?

It's fine, but your are right with your latter questions.

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How will the other OSes be aware of this ?

Should be a standard somewhere.

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I assume there was some repository to maintain such DSDs so that it
is accessible for other OSes. I am not agreeing or disagreeing on the
change itself, but I am concerned about this present in the kernel
code.

I dunno we have a such, but the closest I may imagine is MIPI standardization,
that we have at least for cameras and sound.

I would suggest to go and work with MIPI for network / DSA / etc area, so
everybody else will be aware of the standard.

It is the same argument as for DT. Other OSes and bootloaders seem to
manage digging around in Linux for DT binding documentation. I don't
see why bootloaders and other OSes can not also dig around in Linux
for ACPI binding documentations.

Theoretically you are right. But in DT case majority of non-standard(by
standard I am referring to the one's in Open Firmware specification) are
in the kernel. But that is not true for ACPI. And that is the reason for
objecting it. One of the main other OS using ACPI may not look here for
any ACPI bindings(we may not care, but still OS neutral place is better
for this).

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Ideally, somebody will submit all this for acceptance into ACPI, but
into somebody does, i suspect it will just remain a defacto standard
in Linux.

DSD is not integral part of ACPI spec, so the process is never clear.
However there is this project[1], IIUC it is just guidance and doesn't
include any bindings IIUC. But we need something similar here for better
visibility and to remain OS agnostic. Even with DT, there is a strong
desire to separate it out, but it has grown so much that it is getting
harder to do that with every release. I was just trying to avoid getting
into that situation.

[1] https://github.com/UEFI/DSD-Guide

Here's my personal take on this.

This patch series essentially makes the kernel recognize a few generic
(that is, not tied on any specific device ID) device properties
supplied by the firmware via _DSD.  They are generic, because there is
some library code in the kernel that can consume them and that library
code is used in multiple places (and it is better to supply data from
the firmware directly to it).

If we all agree that it is a good idea for the kernel to allow these
properties to be supplied via _DSD this way, there is no reason to
avoid admitting that fact in the kernel documentation.

IMV, there's nothing wrong with stating officially that these
properties are recognized by the kernel and what they are used for and
it has no bearing on whether or not they are also used by someone
else.

Good point. I was also suggested to make properties have prefix "linux-"
similar to "uefi-" in the set of DSD properties list @[1]. In that case
it makes more sense to maintain in the kernel. If they add "uefi-" prefix,
I was also told that it can be hosted @[1] as specific in section 3.1.4 @[2]

I just sent an update to Documentation with the link to[1]. I can also
update the same to mention about the process as described in section 3.1.4
if that helps and we are happy to follow that in the kernel.

--
Regards,
Sudeep

[1] https://github.com/UEFI/DSD-Guide
[2] https://github.com/UEFI/DSD-Guide/blob/main/src/dsd-guide.adoc#314-adding-uefi-device-properties