Re: [PATCH 6/7] rust: usb: remove the disconnect() callback

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] rust: usb: missing Sync impl for Interface<Bound> breaks
  Driver::Data
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commit 92376533106fabfcec7a799d05c1ddbb68a85c37
Author: Danilo Krummrich <dakr@kernel.org>

rust: usb: remove the disconnect() callback

This commit removes the usb::Driver::disconnect() callback and updates
the trait documentation and USB sample driver to perform device teardown
in Drop or PinnedDrop instead.

> diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
> index 993760ff332b8..2126378abc959 100644
> --- a/rust/kernel/usb.rs
> +++ b/rust/kernel/usb.rs

[ ... ]

> @@ -291,6 +271,10 @@ pub trait Driver {
>      type IdInfo: 'static;
>  
>      /// The type of the driver's bus device private data.
> +    ///
> +    /// Device teardown should be performed in [`Drop`] or [`PinnedDrop`](pin_init::PinnedDrop)
> +    /// for this type. The `'bound` lifetime allows the data to retain device resources and an
> +    /// [`Interface<device::Bound>`] reference for use during teardown.
>      type Data<'bound>: Send + 'bound;

[Severity: Medium]
Can a driver store &'bound Interface<device::Bound> in Driver::Data<'bound>
when Interface<device::Bound> does not implement Sync?

Interface<Ctx> wraps Opaque<bindings::usb_interface> and only implements
Sync for the default Interface<device::Normal> parameter (whereas Sync for
device::Bound was implemented on the private usb::Device type instead).
Because Interface<device::Bound> is !Sync, &'bound Interface<device::Bound>
is !Send and fails to satisfy the Data<'bound>: Send bound at compile time.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261112005455.1224352-1-dakr@kernel.org?part=6