Re: [PATCH v7 3/3] i2c: mux: Propagate software nodes to channel adapters

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Sat, Aug 29, 2026 at 10:04:13PM -0700, Ahmad Byagowi wrote:

Please, stop top-posting!

> Peter, thanks for clarifying.
> The check is intentional as without it, the generic traversal would also
> inspect ACPI firmware nodes and could match _DSD child nodes carrying a
> "reg" property, while the existing ACPI path below uses
> acpi_preset_companion() to associate the adapter by channel address.
> I have not established that, changing the ACPI lookup behavior is safe, and
> that change is not needed for software-node support. With the check
> retained,
> OF and software nodes use the generic lookup, while ACPI continues to
> use the existing acpi_preset_companion() path exclusively.
> That being said, I will clarify that in the commit message for the next
> revision.

Also use proper check then if (!is_acpi_node(...)) or more granular one
(ACPI device or data node in case you we are talking about certain type
 of it).

> On Sat, Aug 29, 2026 at 9:55 PM Peter Rosin <peda@lysator.liu.se> wrote:
> 
> > Den Thu, Aug 27, 2026 at 09:11:31AM +0300, skrev Andy Shevchenko:
> > > On Wed, Aug 26, 2026 at 08:29:47AM -0700, Ahmad Byagowi wrote:

...

> > > Wouldn't it be possible to use some kind of DT overlay to have that?
> >
> > For me, the above is a bit unrelated to this patch series, which is
> > about converting i2c-mux from of-only properties to device properties.
> > That seems like a change that stands on its own.
> >
> > I probably wasn't clear enough with my original question, but what I
> > wondered about was what regression risk that conversion might have
> > for the ACPI case. Specifically, there might be ACPI properties that
> > match what the code is now looking for. It seems unlikely that such
> > properties are actually deployed, but I know next to nothing about
> > ACPI...
> >
> > TL;DR
> >
> > My original question should have been: Is it safe to simply remove
> > these lines from the patch:
> > > +     if (!is_of_node(dev_node) && !is_software_node(dev_node))
> > > +             return NULL;
> > and let the code trawl all kinds of device properties?

-- 
With Best Regards,
Andy Shevchenko