Re: [PATCH] rust: dma: require mutable reference for as_slice_mut() and write()

[Alice Ryhl <aliceryhl@google.com>]

On Sat, Jun 28, 2025 at 06:49:54PM +0200, Danilo Krummrich wrote:
> Given the safety requirements of as_slice_mut() and write() taking an
> immutable reference is technically not incorrect.
> 
> However, let's leverage the compiler's capabilities and require a
> mutable reference to ensure exclusive access.
> 
> This also fixes a clippy warning introduced with 1.88:
> 
>   warning: mutable borrow from immutable input(s)
>      --> rust/kernel/dma.rs:297:78
>       |
>   297 |     pub unsafe fn as_slice_mut(&self, offset: usize, count: usize) -> Result<&mut [T]> {
>       |                                                                              ^^^^^^^^
> 
> Fixes: d37a39f607c4 ("rust: dma: add as_slice/write functions for CoherentAllocation")
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>

I'm not sure if `as_slice_mut()` is exactly the right API we want
long-term, but this is a step in the right direction.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>