Re: [PATCH v3 02/10] software node: increase the reference of the swnode by its fwnode

Andy Shevchenko
2025-10-31T12:32:06Z

On Fri, Oct 31, 2025 at 05:27:10AM -0500, Bartosz Golaszewski wrote:
> On Fri, 31 Oct 2025 10:44:46 +0100, Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> said:
> > On Fri, Oct 31, 2025 at 10:03:47AM +0100, Bartosz Golaszewski wrote:
> >> On Fri, Oct 31, 2025 at 9:30 AM Andy Shevchenko
> >> <andriy.shevchenko@linux.intel.com> wrote:
> >> > On Thu, Oct 30, 2025 at 03:33:02AM -0700, Bartosz Golaszewski wrote:
> >> > > On Thu, 30 Oct 2025 10:34:46 +0100, Andy Shevchenko
> >> > > <andriy.shevchenko@linux.intel.com> said:

...

> >> > > Andy: the resulting code after patch 3/10 looks like this:
> >> > >
> >> > > struct fwnode_handle *refnode;
> >> > >
> >> > > (...)
> >> >
> >> > Let's say something like below to be put here
> >> >
> >> > /*
> >> > * The reference in software node may refer to a node of a different type.
> >> > * Depending on the type we choose either to use software node directly, or
> >> > * delegate that to fwnode API.
> >> > */
> >>
> >> But this is incorrect: we're not really doing that. We either use the
> >> firmware node reference directly OR cast the software node to its
> >> firmware node representation. We ALWAYS use the firmware node API
> >> below.
> >>
> >> This really *is* evident from the code but if it'll make you happy and
> >> make you sign off on this, I'll add a corrected version.
> >
> > The comment should answer to the Q: "Why the heck are we calling fwnode APIs here?"
> >
> >> IMO It's completely redundant.
> >
> > This is unusual case for swnode API (see other functions, they call directly
> > the low-level implementation instead of going to a round via fwnode). That's
> > why I insist on a comment of this piece. It may be obvious for you, but the
> > unprepared read would be surprised by this inconsistency.
> >
>
> I propose to have the following:
>
> + /*
> + * A software node can reference other software nodes or firmware
> + * nodes (which are the abstraction layer sitting on top of them).
> + * This is done to ensure we can create references to static software
> + * nodes before they're registered with the firmware node framework.
> + * At the time the reference is being resolved, we expect the swnodes
> + * in question to already have been registered and to be backed by
> + * a firmware node. This is why we use the fwnode API below to read the
> + * relevant properties and bump the reference count.
> + */
>
> This at least adds relevant information on *why* we're using the fwnode API.

Yes, works for me, thanks!

--
With Best Regards,
Andy Shevchenko