[PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Miguel Ojeda]

Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
introducing a new lint `clippy::map_or_identity` [1][2], which currently
triggers in a single case:

    warning: expression can be simplified using `Result::unwrap_or()`
        --> rust/kernel/cpufreq.rs:1326:60
         |
    1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
         |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
         = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
         = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
    help: consider using `unwrap_or`
         |
    1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
    1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
         |

The suggestion is valid, thus clean it up.

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/cpufreq.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/kernel/cpufreq.rs b/rust/kernel/cpufreq.rs
index d8d26870bea2..a20bd5006f38 100644
--- a/rust/kernel/cpufreq.rs
+++ b/rust/kernel/cpufreq.rs
@@ -1323,7 +1323,7 @@ impl<T: Driver> Registration<T> {
         // SAFETY: The C API guarantees that `cpu` refers to a valid CPU number.
         let cpu_id = unsafe { CpuId::from_u32_unchecked(cpu) };
 
-        PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
+        PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
     }
 
     /// Driver's `update_limit` callback.

base-commit: 420dd187e1572bb7e232781bc4377a80c8eb64fb
-- 
2.54.0

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Alexandre Courbot]

On Sat May 30, 2026 at 6:58 PM JST, Miguel Ojeda wrote:
> Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> introducing a new lint `clippy::map_or_identity` [1][2], which currently
> triggers in a single case:
>
>     warning: expression can be simplified using `Result::unwrap_or()`
>         --> rust/kernel/cpufreq.rs:1326:60
>          |
>     1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>          |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>          |
>          = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
>          = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
>          = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
>     help: consider using `unwrap_or`
>          |
>     1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>     1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>          |
>
> The suggestion is valid, thus clean it up.
>
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Gary Guo]

On Sat May 30, 2026 at 10:58 AM BST, Miguel Ojeda wrote:
> Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> introducing a new lint `clippy::map_or_identity` [1][2], which currently
> triggers in a single case:
> 
>     warning: expression can be simplified using `Result::unwrap_or()`
>         --> rust/kernel/cpufreq.rs:1326:60
>          |
>     1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>          |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>          |
>          = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
>          = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
>          = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
>     help: consider using `unwrap_or`
>          |
>     1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>     1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>          |
> 
> The suggestion is valid, thus clean it up.
> 
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

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

> ---
>  rust/kernel/cpufreq.rs | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Miguel Ojeda]

On Sat, May 30, 2026 at 11:58 AM Miguel Ojeda <ojeda@kernel.org> wrote:
>
> Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> introducing a new lint `clippy::map_or_identity` [1][2], which currently
> triggers in a single case:
>
>     warning: expression can be simplified using `Result::unwrap_or()`
>         --> rust/kernel/cpufreq.rs:1326:60
>          |
>     1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>          |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>          |
>          = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
>          = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
>          = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
>     help: consider using `unwrap_or`
>          |
>     1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>     1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>          |
>
> The suggestion is valid, thus clean it up.
>
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Viresh, Rafael: I can put this into `rust-next` if you prefer (I
considered `rust-fixes`, but it is not important enough at this
stage).

Cheers,
Miguel

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Zhongqiu Han]

On 5/30/2026 5:58 PM, Miguel Ojeda wrote:
> Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> introducing a new lint `clippy::map_or_identity` [1][2], which currently
> triggers in a single case:
> 
>      warning: expression can be simplified using `Result::unwrap_or()`
>          --> rust/kernel/cpufreq.rs:1326:60
>           |
>      1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>           |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>           |
>           = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
>           = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
>           = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
>      help: consider using `unwrap_or`
>           |
>      1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>      1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>           |
> 
> The suggestion is valid, thus clean it up.
> 
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>


Reviewed-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>


> ---
>   rust/kernel/cpufreq.rs | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/rust/kernel/cpufreq.rs b/rust/kernel/cpufreq.rs
> index d8d26870bea2..a20bd5006f38 100644
> --- a/rust/kernel/cpufreq.rs
> +++ b/rust/kernel/cpufreq.rs
> @@ -1323,7 +1323,7 @@ impl<T: Driver> Registration<T> {
>           // SAFETY: The C API guarantees that `cpu` refers to a valid CPU number.
>           let cpu_id = unsafe { CpuId::from_u32_unchecked(cpu) };
>   
> -        PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
> +        PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>       }
>   
>       /// Driver's `update_limit` callback.
> 
> base-commit: 420dd187e1572bb7e232781bc4377a80c8eb64fb


-- 
Thx and BRs,
Zhongqiu Han

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Viresh Kumar]

On 30-05-26, 13:34, Miguel Ojeda wrote:
> On Sat, May 30, 2026 at 11:58 AM Miguel Ojeda <ojeda@kernel.org> wrote:
> >
> > Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> > introducing a new lint `clippy::map_or_identity` [1][2], which currently
> > triggers in a single case:
> >
> >     warning: expression can be simplified using `Result::unwrap_or()`
> >         --> rust/kernel/cpufreq.rs:1326:60
> >          |
> >     1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
> >          |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >          |
> >          = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
> >          = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
> >          = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
> >     help: consider using `unwrap_or`
> >          |
> >     1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
> >     1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
> >          |
> >
> > The suggestion is valid, thus clean it up.
> >
> > Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> > Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> > Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> > Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> 
> Viresh, Rafael: I can put this into `rust-next` if you prefer (I
> considered `rust-fixes`, but it is not important enough at this
> stage).

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Miguel Ojeda]

On Sat, May 30, 2026 at 11:58 AM Miguel Ojeda <ojeda@kernel.org> wrote:
>
> Starting with Rust 1.98.0 (expected 2026-08-20), Clippy is likely
> introducing a new lint `clippy::map_or_identity` [1][2], which currently
> triggers in a single case:
>
>     warning: expression can be simplified using `Result::unwrap_or()`
>         --> rust/kernel/cpufreq.rs:1326:60
>          |
>     1326 |         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>          |                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>          |
>          = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_or_identity
>          = note: `-W clippy::map-or-identity` implied by `-W clippy::all`
>          = help: to override `-W clippy::all` add `#[allow(clippy::map_or_identity)]`
>     help: consider using `unwrap_or`
>          |
>     1326 -         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
>     1326 +         PolicyCpu::from_cpu(cpu_id).map_or(0, |mut policy| T::get(&mut policy).unwrap_or(0))
>          |
>
> The suggestion is valid, thus clean it up.
>
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
> Link: https://github.com/rust-lang/rust-clippy/issues/15801 [1]
> Link: https://github.com/rust-lang/rust-clippy/pull/16052 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Applied to `rust-next` -- thanks everyone!

Cheers,
Miguel

Re: [PATCH] rust: cpufreq: clean new `clippy::map_or_identity` lint for Rust 1.98.0

[Miguel Ojeda]

On Sat, May 30, 2026 at 11:58 AM Miguel Ojeda <ojeda@kernel.org> wrote:
>
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).

Adjusted to "6.18.y and later", since `cpufreq` was not there in 6.12.y anyway.

(I didn't use Fixes: because it isn't really a fix, although as usual
it depends on how one thinks about those...)

Cheers,
Miguel