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

[Guilherme Giácomo Simões]

Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> On Mon, Sep 30, 2024 at 10:52:27AM -0300, Guilherme Giácomo Simões wrote:
> > Danilo Krummrich <dakr@xxxxxxxxxx> 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.

Okay, I understand now that the .into() call, also call `inc_ref` that I
was don't have knowing. This body change of the get_device() really make
sense, and I will send a v4 patch.

Thanks for this Mr. Krummrich.