Hi Greg, Sasha,

Please consider commit f0915acd1fc6 ("rust: give Clippy the minimum supported Rust version") for 6.12.y. It should cherry-pick

It will clean a lint starting with Rust 1.90.0 (expected 2025-09-18) -- more details below [1]. Moreover, it also aligns us with 6.15.y and mainline in terms of Clippy behavior, which also helps.

It is pretty safe, since it is just a config option for Clippy. Even if a bug were to occur that somehow broke it only in stable, normal kernel builds do not use Clippy to begin with.

Thanks!

Cheers, Miguel

[1]

Starting with Rust 1.90.0 (expected 2025-09-18), Clippy detects manual implementations of `is_multiple_of`, of which we have one in the QR code panic code:

warning: manual implementation of `.is_multiple_of()` --> drivers/gpu/drm/drm_panic_qr.rs:886:20 | 886 | if (x ^ y) % 2 == 0 && !self.is_reserved(x, y) { | ^^^^^^^^^^^^^^^^ help: replace with: `(x ^ y).is_multiple_of(2)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_multiple... = note: `-W clippy::manual-is-multiple-of` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::manual_is_multiple_of)]`

While in general `is_multiple_of` does not have the same behavior as `b == 0` [2], in this case the suggestion is fine.

However, we cannot use `is_multiple_of` yet because it was introduced (unstably) in Rust 1.81.0, and we still support Rust 1.78.0.

Normally, we would conditionally allow it (which is what I was going to do in a patch for mainline), but it turns out we don't trigger it in mainline nor 6.15.y because of the `msrv` config option which makes Clippy avoid the lint.

Thus, instead of a custom patch, I decided to align Clippy here by backporting the config option instead.

Link: https://github.com/rust-lang/rust-clippy/issues/15335 [2]