[REGRESSION] stable-rc/linux-6.6.y: (build) incompatible function pointer types initializing 'void (*)(struct ...

[REGRESSION] stable-rc/linux-6.6.y: (build) incompatible function pointer types initializing 'void (*)(struct ...

[KernelCI bot]

New build issue found on stable-rc/linux-6.6.y:

---
 incompatible function pointer types initializing 'void (*)(struct cpufreq_policy *)' with an expression of type 'int (struct cpufreq_policy *)' [-Wincompatible-function-pointer-types] in drivers/cpufreq/cpufreq-nforce2.o (drivers/cpufreq/cpufreq-nforce2.c) [logspec:kbuild,kbuild.compiler.error]
---

Log excerpt:
=====================================================
drivers/cpufreq/cpufreq-nforce2.c:376:10: error: incompatible function pointer types initializing 'void (*)(struct cpufreq_policy *)' with an expression of type 'int (struct cpufreq_policy *)' [-Wincompatible-function-pointer-types]
  376 |         .exit = nforce2_cpu_exit,
      |                 ^~~~~~~~~~~~~~~~
1 error generated.

=====================================================

When fixing this issue, please attribute this report according to the
patch submission rules:

Reported-by: kernelci.org bot <bot@kernelci.org>

For complete logs and details about the environment used, see the issue
on the KernelCI dashboard:

- dashboard: https://d.kernelci.org/i/maestro:b41ef2d63eb41045cf02fd8039a4bbd582611f85
- giturl: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
- commit HEAD:  5b1c90a58c8928f66eb8b2599574ea802cdb060f

# Builds where the incident occurred:

## i386_defconfig+allmodconfig+CONFIG_FRAME_WARN=2048 on (i386):
- compiler: clang-21
- config: https://files.kernelci.org/kbuild-clang-21-i386-allmodconfig-6a5f9ea675cb84fb216f9d44/.config
- dashboard: https://d.kernelci.org/build/maestro:6a5f9ea675cb84fb216f9d44

#kernelci issue maestro:b41ef2d63eb41045cf02fd8039a4bbd582611f85

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Re: [REGRESSION] stable-rc/linux-6.6.y: (build) incompatible function pointer types initializing 'void (*)(struct ...

[Sasha Levin]

On Tue, Jul 21, 2026 at 10:59:07PM -0000, KernelCI bot wrote:
> New build issue found on stable-rc/linux-6.6.y:
>
> drivers/cpufreq/cpufreq-nforce2.c:376:10: error: incompatible function pointer types initializing 'void (*)(struct cpufreq_policy *)' with an expression of type 'int (struct cpufreq_policy *)' [-Wincompatible-function-pointer-types]

This was caused by an incomplete backport of b4b1ddc9dfe9 ("cpufreq:
Make cpufreq_driver::exit() return void"): 6.6 still has drivers
(nforce2, loongson2, ia64-acpi-cpufreq) whose int-returning exit()
callbacks were removed upstream by prerequisite commits that were
never queued.

Dropped the offending patch from the 6.6 queue along with its
dependencies:
  - "cpufreq: pcc: Remove empty exit() callback"
  - "cpufreq: qcom-cpufreq-hw: Fix possible double free" (will be
    requeued separately as a context-adjusted backport)

Thanks for the report.

-- 
Thanks,
Sasha