Re: [PATCH] rust: usb: fix broken call to T::disconnect()

Daniel Almeida
2025-11-03T23:38:43Z

> On 3 Nov 2025, at 08:01, Danilo Krummrich <dakr@kernel.org> wrote:
>
> A refactoring of Device::drvdata_obtain() broke T::disconnect() in the
> USB abstractions.
>
> """
> error[E0599]: no method named `data` found for struct `core::pin::Pin<kbox::Box<T, Kmalloc>>` in the current scope
> --> rust/kernel/usb.rs:92:34
> |
> 92 | T::disconnect(intf, data.data());
> | ^^^^ method not found in `core::pin::Pin<kbox::Box<T, Kmalloc>>`
>
> error: aborting due to 1 previous error
>
> For more information about this error, try `rustc --explain E0599`.
> make[2]: *** [rust/Makefile:553: rust/kernel.o] Error 1
> make[1]: *** [/builddir/build/BUILD/kernel-6.18.0-build/kernel-next-20251103/linux-6.18.0-0.0.next.20251103.436.vanilla.fc44.x86_64/Makefile:1316: prepare] Error 2
> make: *** [Makefile:256: __sub-make] Error 2
> """
>
> This slipped through, since the USB abstractions are globally disabled.
> However, the USB tree recently enabled them, hence it showed up in
> linux-next.
>
> Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
> Closes: https://lore.kernel.org/all/1c8afbc0-e888-4702-9e4e-fa8aef0f97ae@leemhuis.info/
> Fixes: 6bbaa93912bf ("rust: device: narrow the generic of drvdata_obtain()")
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
> rust/kernel/usb.rs | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
> index 92215fdc3c6a..534e3ded5442 100644
> --- a/rust/kernel/usb.rs
> +++ b/rust/kernel/usb.rs
> @@ -89,7 +89,7 @@ extern "C" fn disconnect_callback(intf: *mut bindings::usb_interface) {
> // and stored a `Pin<KBox<T>>`.
> let data = unsafe { dev.drvdata_obtain::<T>() };
>
> - T::disconnect(intf, data.data());
> + T::disconnect(intf, data.as_ref());
> }
> }
>
> --
> 2.51.0
>
>

Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>