On Tue Jun 24, 2025 at 4:33 PM CEST, Boqun Feng wrote:
> On Tue, Jun 24, 2025 at 02:50:23PM +0100, Alice Ryhl wrote:
>> On Tue, Jun 24, 2025 at 1:46 PM Benno Lossin <lossin@xxxxxxxxxx> wrote:
>> > On Tue Jun 24, 2025 at 2:31 PM CEST, Daniel Almeida wrote:
>> > > On 23 Jun 2025, at 16:28, Benno Lossin <lossin@xxxxxxxxxx> wrote:
>> > >> On Mon Jun 23, 2025 at 9:18 PM CEST, Boqun Feng wrote:
>> > >>> try_pin_init!(&this in Self {
>> > >>> handler,
>> > >>> inner: Devres::new(
>> > >>> dev,
>> > >>> RegistrationInner {
>> > >>> // Needs to use `handler` address as cookie, same for
>> > >>> // request_irq().
>> > >>> cookie: &raw (*(this.as_ptr().cast()).handler),
>> > >>> irq: {
>> > >>> to_result(unsafe { bindings::request_irq(...) })?;
>> > >>> irq
>> > >>> }
>> > >>> },
>> > >>> GFP_KERNEL,
>> > >>> )?,
>> > >>> _pin: PhantomPinned
>> > >>> })
>> > >>
>> > >> Well yes and no, with the Devres changes, the `cookie` can just be the
>> > >> address of the `RegistrationInner` & we can do it this way :)
>> > >>
>> > >> ---
>> > >> Cheers,
>> > >> Benno
>> > >
>> > >
>> > > No, we need this to be the address of the the whole thing (i.e.
>> > > Registration<T>), otherwise you can’t access the handler in the irq
>> > > callback.
>
> You only need the access of `handler` in the irq callback, right? I.e.
> passing the address of `handler` would suffice (of course you need
> to change the irq callback as well).
>
>> >
>> > Gotcha, so you keep the cookie field, but you should still be able to
>> > use `try_pin_init` & the devres improvements to avoid the use of
>> > `pin_init_from_closure`.
>>
>> It sounds like this is getting too complicated and that
>> `pin_init_from_closure` is the simpler way to go.
The current code is not correct and the version that Boqun has below
looks pretty correct (and much simpler).
> Even if we use `pin_init_from_closure`, we still need the other
> `try_pin_init` anyway for `Devres::new()` (or alternatively we can
> implement a `RegistrationInner::new()`).
>
> Below is what would look like with the Devres changes in mind:
>
>
> try_pin_init!(&this in Self {
> handler,
> inner: <- Devres::new(
> dev,
> try_pin_init!( RegistrationInner {
> // Needs to use `handler` address as cookie, same for
> // request_irq().
> cookie: &raw (*(this.as_ptr().cast()).handler),
> // @Benno, would this "this" work here?
Yes.
> irq: {
> to_result(unsafe { bindings::request_irq(...) })?;
> irq
> }
> }),
> )?,
> _pin: PhantomPinned
> })
---
Cheers,
Benno
