Re: [PATCH] rust: irq: move 'static bounds to traits

[Gary Guo <gary@garyguo.net>]

On 2026-02-19 09:12, Alice Ryhl wrote:
> The 'static bound is required by all irq handlers, so it is simpler to
> specify it on the trait declaration instead of repeating it every time
> the trait is used as a where clause. Note that we already list Sync on
> the trait bound for the same reason.
> 
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Thanks, this is much cleaner.

Reviewed-by: Gary Guo <gary@garyguo.net>

Best,
Gary

> ---
> Follow up to:
> https://lore.kernel.org/all/20260214092740.3201946-1-lossin@kernel.org/
> ---
>  rust/kernel/irq/request.rs | 28 +++++++++++-----------------
>  1 file changed, 11 insertions(+), 17 deletions(-)
> 
> diff --git a/rust/kernel/irq/request.rs b/rust/kernel/irq/request.rs
> index 
> 2ceeaeb0543a4ef0d4f25ca600dc4770f97085c5..e207707156094b1bbf1af0292cff8ed27ea64207 
> 100644
> --- a/rust/kernel/irq/request.rs
> +++ b/rust/kernel/irq/request.rs
> @@ -27,7 +27,7 @@ pub enum IrqReturn {
>  }
> 
>  /// Callbacks for an IRQ handler.
> -pub trait Handler: Sync {
> +pub trait Handler: Sync + 'static {
>      /// The hard IRQ handler.
>      ///
>      /// This is executed in interrupt context, hence all corresponding
> @@ -45,7 +45,7 @@ fn handle(&self, device: &Device<Bound>) -> IrqReturn 
> {
>      }
>  }
> 
> -impl<T: ?Sized + Handler, A: Allocator> Handler for Box<T, A> {
> +impl<T: ?Sized + Handler, A: Allocator + 'static> Handler for Box<T, 
> A> {
>      fn handle(&self, device: &Device<Bound>) -> IrqReturn {
>          T::handle(self, device)
>      }
> @@ -182,7 +182,7 @@ pub fn irq(&self) -> u32 {
>  ///
>  /// * We own an irq handler whose cookie is a pointer to `Self`.
>  #[pin_data]
> -pub struct Registration<T: Handler + 'static> {
> +pub struct Registration<T: Handler> {
>      #[pin]
>      inner: Devres<RegistrationInner>,
> 
> @@ -195,7 +195,7 @@ pub struct Registration<T: Handler + 'static> {
>      _pin: PhantomPinned,
>  }
> 
> -impl<T: Handler + 'static> Registration<T> {
> +impl<T: Handler> Registration<T> {
>      /// Registers the IRQ handler with the system for the given IRQ 
> number.
>      pub fn new<'a>(
>          request: IrqRequest<'a>,
> @@ -261,10 +261,7 @@ pub fn synchronize(&self, dev: &Device<Bound>) -> 
> Result {
>  /// # Safety
>  ///
>  /// This function should be only used as the callback in 
> `request_irq`.
> -unsafe extern "C" fn handle_irq_callback<T: Handler + 'static>(
> -    _irq: i32,
> -    ptr: *mut c_void,
> -) -> c_uint {
> +unsafe extern "C" fn handle_irq_callback<T: Handler>(_irq: i32, ptr: 
> *mut c_void) -> c_uint {
>      // SAFETY: `ptr` is a pointer to `Registration<T>` set in 
> `Registration::new`
>      let registration = unsafe { &*(ptr as *const Registration<T>) };
>      // SAFETY: The irq callback is removed before the device is 
> unbound, so the fact that the irq
> @@ -288,7 +285,7 @@ pub enum ThreadedIrqReturn {
>  }
> 
>  /// Callbacks for a threaded IRQ handler.
> -pub trait ThreadedHandler: Sync {
> +pub trait ThreadedHandler: Sync + 'static {
>      /// The hard IRQ handler.
>      ///
>      /// This is executed in interrupt context, hence all corresponding
> @@ -319,7 +316,7 @@ fn handle_threaded(&self, device: &Device<Bound>) 
> -> IrqReturn {
>      }
>  }
> 
> -impl<T: ?Sized + ThreadedHandler, A: Allocator> ThreadedHandler for 
> Box<T, A> {
> +impl<T: ?Sized + ThreadedHandler, A: Allocator + 'static> 
> ThreadedHandler for Box<T, A> {
>      fn handle(&self, device: &Device<Bound>) -> ThreadedIrqReturn {
>          T::handle(self, device)
>      }
> @@ -403,7 +400,7 @@ fn handle_threaded(&self, device: &Device<Bound>) 
> -> IrqReturn {
>  ///
>  /// * We own an irq handler whose cookie is a pointer to `Self`.
>  #[pin_data]
> -pub struct ThreadedRegistration<T: ThreadedHandler + 'static> {
> +pub struct ThreadedRegistration<T: ThreadedHandler> {
>      #[pin]
>      inner: Devres<RegistrationInner>,
> 
> @@ -416,7 +413,7 @@ pub struct ThreadedRegistration<T: ThreadedHandler 
> + 'static> {
>      _pin: PhantomPinned,
>  }
> 
> -impl<T: ThreadedHandler + 'static> ThreadedRegistration<T> {
> +impl<T: ThreadedHandler> ThreadedRegistration<T> {
>      /// Registers the IRQ handler with the system for the given IRQ 
> number.
>      pub fn new<'a>(
>          request: IrqRequest<'a>,
> @@ -483,7 +480,7 @@ pub fn synchronize(&self, dev: &Device<Bound>) -> 
> Result {
>  /// # Safety
>  ///
>  /// This function should be only used as the callback in 
> `request_threaded_irq`.
> -unsafe extern "C" fn handle_threaded_irq_callback<T: ThreadedHandler + 
> 'static>(
> +unsafe extern "C" fn handle_threaded_irq_callback<T: ThreadedHandler>(
>      _irq: i32,
>      ptr: *mut c_void,
>  ) -> c_uint {
> @@ -499,10 +496,7 @@ pub fn synchronize(&self, dev: &Device<Bound>) -> 
> Result {
>  /// # Safety
>  ///
>  /// This function should be only used as the callback in 
> `request_threaded_irq`.
> -unsafe extern "C" fn thread_fn_callback<T: ThreadedHandler + 'static>(
> -    _irq: i32,
> -    ptr: *mut c_void,
> -) -> c_uint {
> +unsafe extern "C" fn thread_fn_callback<T: ThreadedHandler>(_irq: i32, 
> ptr: *mut c_void) -> c_uint {
>      // SAFETY: `ptr` is a pointer to `ThreadedRegistration<T>` set in 
> `ThreadedRegistration::new`
>      let registration = unsafe { &*(ptr as *const 
> ThreadedRegistration<T>) };
>      // SAFETY: The irq callback is removed before the device is 
> unbound, so the fact that the irq
> 
> ---
> base-commit: a58b8764aed9648357b1c5b6368c9943ba33b7f9
> change-id: 20260219-irq-static-on-trait-5b267c7a4375
> 
> Best regards,