Re: [PATCH v2 1/1] device: rust: change the name function

[Danilo Krummrich <dakr@kernel.org>]

On Mon, Sep 30, 2024 at 10:52:27AM -0300, Guilherme Giácomo Simões wrote:
> Danilo Krummrich <dakr@kernel.org> writes:
> > > diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
> > > index 851018eef885..ecffaff041e0 100644
> > > --- a/rust/kernel/device.rs
> > > +++ b/rust/kernel/device.rs
> > > @@ -51,7 +51,7 @@ impl Device {
> > >      ///
> > >      /// It must also be ensured that `bindings::device::release` can be called from any thread.
> > >      /// While not officially documented, this should be the case for any `struct device`.
> > > -    pub unsafe fn from_raw(ptr: *mut bindings::device) -> ARef<Self> {
> > > +    pub unsafe fn get_device(ptr: *mut bindings::device) -> ARef<Self> {
> >
> > As a follow-up, it probably makes sense to also change the function body to
> > just: `unsafe { Self::as_ref(ptr) }.into()`.
> 
> But if we change the function body that is suggested for you, the
> function will not have your own refcount. If I don't wrong, the
> Device::as_ref() expects the caller to have its own reference counter.
> And if we change the behavior of function, your name don't need to be
> changed, because your behavior will be equal the from_raw() from
> standard library.

I think you missed the `into()` above. This will convert `&'a Device` into
`ARef<Device>`, and also call `inc_ref` from the `AlwaysRefCounted` trait
implemented for `Device`, and hence increase the reference count.