On Mon, Jun 9, 2025 at 12:47 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> On Sun, Jun 08, 2025 at 07:51:08PM -0300, Daniel Almeida wrote:
> > + dev: &'a Device<Bound>,
> > + irq: u32,
> > + flags: Flags,
> > + name: &'static CStr,
> > + handler: T,
> > + ) -> impl PinInit<Self, Error> + 'a {
> > + let closure = move |slot: *mut Self| {
> > + // SAFETY: The slot passed to pin initializer is valid for writing.
> > + unsafe {
> > + slot.write(Self {
> > + inner: Devres::new(
> > + dev,
> > + RegistrationInner {
> > + irq,
> > + cookie: slot.cast(),
> > + },
> > + GFP_KERNEL,
> > + )?,
> > + handler,
> > + _pin: PhantomPinned,
> > + })
> > + };
> > +
> > + // SAFETY:
> > + // - The callbacks are valid for use with request_irq.
> > + // - If this succeeds, the slot is guaranteed to be valid until the
> > + // destructor of Self runs, which will deregister the callbacks
> > + // before the memory location becomes invalid.
> > + let res = to_result(unsafe {
> > + bindings::request_irq(
> > + irq,
> > + Some(handle_irq_callback::<T>),
> > + flags.into_inner() as usize,
> > + name.as_char_ptr(),
> > + slot.cast(),
> > + )
> > + });
> > +
> > + if res.is_err() {
> > + // SAFETY: We are returning an error, so we can destroy the slot.
> > + unsafe { core::ptr::drop_in_place(&raw mut (*slot).handler) };
> > + }
> > +
> > + res
> > + };
> > +
> > + // SAFETY:
> > + // - if this returns Ok, then every field of `slot` is fully
> > + // initialized.
> > + // - if this returns an error, then the slot does not need to remain
> > + // valid.
> > + unsafe { pin_init_from_closure(closure) }
>
> Can't we use try_pin_init!() instead, move request_irq() into the initializer of
> RegistrationInner and initialize inner last?
We need a pointer to the entire struct when calling
bindings::request_irq. I'm not sure this allows you to easily get one?
I don't think using container_of! here is worth it.
Alice
