Re: [PATCH v7 3/9] samples: rust: platform: conditionally call Self::properties_parse()

From: Danilo Krummrich
Date: Thu Jun 19 2025 - 13:59:39 EST


On Wed, Jun 18, 2025 at 04:11:57PM +0200, Danilo Krummrich wrote:
> On Wed, Jun 18, 2025 at 08:19:58AM -0500, Rob Herring wrote:
> > On Wed, Jun 18, 2025 at 11:13:25AM +0100, Igor Korotin wrote:
> > > From: Danilo Krummrich <dakr@xxxxxxxxxx>
> > >
> > > Only call Self::properties_parse() when the device is compatible with
> > > "test,rust-device".
> > >
> > > Once we add ACPI support, we don't want the ACPI device to fail probing
> > > in Self::properties_parse().
> > >
> > > Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
> >
> > This needs your S-o-b as well since you sent the patch.
> >
> > > ---
> > > samples/rust/rust_driver_platform.rs | 7 ++++++-
> > > 1 file changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
> > > index 000bb915af60..036dd0b899b0 100644
> > > --- a/samples/rust/rust_driver_platform.rs
> > > +++ b/samples/rust/rust_driver_platform.rs
> > > @@ -40,7 +40,12 @@ fn probe(
> > > dev_info!(dev, "Probed with info: '{}'.\n", info.0);
> > > }
> > >
> > > - Self::properties_parse(dev)?;
> > > + if dev
> > > + .fwnode()
> > > + .is_some_and(|node| node.is_compatible(c_str!("test,rust-device")))
> >
> > I think you should be checking just is this ACPI or DT rather than
> > compatible. It's kind of an anti-pattern to test compatible in probe.
> > The reason is we've already matched to a compatible and have match data
> > to use, so we don't need to do it again. It becomes quite messy when
> > there are numerous possible compatibles.
>
> Yeah, that was my first approach; here's the patch from a few days ago [1].
>
> The reason why I decided against this, was that all the properties we check in
> Self::properties_parse() in a fallible way *only* apply to the device with this
> compatible string.
>
> But I don't mind if we replace it with [1] either.

As mentioned, I don't mind either, so let's change it up.

@Igor, can you please pick up the patch in [1] and at the same time drop the
patch introducing FwNode::is_compatible() and replace node.is_compatible() with
node.is_of_node() in this one?

Please also remember to add your SoB to the patches not authored by yourself.

Thanks,
Danilo

> [1] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/commit/?h=rust/is_of_node