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

[Igor Korotin <igor.korotin.linux@gmail.com>]

On 6/19/25 18:59, Danilo Krummrich wrote:
> 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@kernel.org>
>>>>
>>>> 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@kernel.org>
>>>
>>> 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?

Just to make sure that we're on the same page, I replace this:

    if dev.fwnode().is_some_and(|node|
node.is_compatible(c_str!("test,rust-device")))

with:

    if dev.fwnode().is_some_and(|node| node.is_of_node())

And reworded the comment as follows:

    samples: rust: platform: conditionally call Self::properties_parse()

    Only call Self::properties_parse() when the device is OF node

    Once we add ACPI support, we don't want the ACPI device to fail probing
    in Self::properties_parse().


Thanks
Igor