Re: [PATCH 01/17] rust: sync: completion: add wait_for_completion_timeout()

[John Hubbard]

On 8/8/26 7:40 PM, Alexandre Courbot wrote:
> On Sat Aug 8, 2026 at 12:11 PM JST, John Hubbard wrote:
> > From: Joel Fernandes <joelagnelf@xxxxxxxxxx>
> >
> > A driver that runs an interrupt self-test during probe waits for the
> > handler to fire. wait_for_completion() has no timeout, so a broken
> > interrupt path stalls probe indefinitely. Add a timeout variant of
> > wait_for_completion().
> >
> > Document the type invariant that Completion always holds an initialized
> > struct completion, and cite it in the SAFETY comments.
>
> That last paragraph (and the associated hunks below) are a different
> thing, and should be its own patch.

OK.

> <...>
> >   /// Synchronization primitive to signal when a certain task has been completed.
> >   ///
> >   /// The [`Completion`] synchronization primitive signals when a certain task has been completed by
> >   /// waking up other tasks that have been queued up to wait for the [`Completion`] to be completed.
> >   ///
> > +/// # Invariants
> > +///
> > +/// `inner` always holds an initialized `struct completion`.
> > +///
> >   /// # Examples
> >   ///
> >   /// ```
> > @@ -96,7 +105,8 @@ fn as_raw(&self) -> *mut bindings::completion {
> >       /// completion is permanently done, i.e. signals all current and future waiters.
> >       #[inline]
> >       pub fn complete_all(&self) {
> > -        // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
> > +        // SAFETY: By the type invariant, `self.as_raw()` is a pointer to an initialized
> > +        // `struct completion`.
> >           unsafe { bindings::complete_all(self.as_raw()) };
> >       }
> >   
> > @@ -108,7 +118,25 @@ pub fn complete_all(&self) {
> >       /// See also [`Completion::complete_all`].
> >       #[inline]
> >       pub fn wait_for_completion(&self) {
> > -        // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
> > +        // SAFETY: By the type invariant, `self.as_raw()` is a pointer to an initialized
> > +        // `struct completion`.
> >           unsafe { bindings::wait_for_completion(self.as_raw()) };
> >       }
>
> These hunks are what should be extracted, or even dropped as
> `wait_for_completion_timeout` doesn't add any extra requirement for
> them.
OK, I'll just drop those entirely.

thanks,
--
John Hubbard