[PATCH v3] cpuidle: psci: Init cpuidle only for present CPUs

[Ulf Hansson]

On Thu, 6 Mar 2025 at 07:17, Jacky Bai <ping.bai at nxp.com> wrote:
>
> for_each_possible_cpu() is currently used to initialize cpuidle
> in the PSCI cpuidle driver.
>
> However, in cpu_dev_register_generic(), for_each_present_cpu()
> is used to register CPU devices which means the CPU devices are
> only registered for present CPUs and not all possible CPUs.
>
> With nosmp or maxcpus=0, only the boot CPU is present, leading
> to the failure:
>
>   |  Failed to register cpuidle device for cpu1
>
> Change for_each_possible_cpu() to for_each_present_cpu() in the
> PSCI cpuidle driver to ensure it only registers cpuidle devices
> for CPUs that are actually present.
>
> Fixes: b0c69e1214bc ("drivers: base: Use present CPUs in GENERIC_CPU_DEVICES")
> Reviewed-by: Dhruva Gole <d-gole at ti.com>
> Reviewed-by: Sudeep Holla <sudeep.holla at arm.com>
> Tested-by: Yuanjie Yang <quic_yuanjiey at quicinc.com>
> Signed-off-by: Jacky Bai <ping.bai at nxp.com>

Is this problem specific to cpuidle-psci?

Others are using for_each_possible_cpu() when registering their cpuidle drivers.

Kind regards
Uffe

> ---
>  - v2 changes:
>   - Improve the changelog as suggested by Sudeep
> ---
>  drivers/cpuidle/cpuidle-psci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
> index 2562dc001fc1..00117e9b33e8 100644
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -410,7 +410,7 @@ static int psci_cpuidle_probe(struct platform_device *pdev)
>         struct cpuidle_driver *drv;
>         struct cpuidle_device *dev;
>
> -       for_each_possible_cpu(cpu) {
> +       for_each_present_cpu(cpu) {
>                 ret = psci_idle_init_cpu(&pdev->dev, cpu);
>                 if (ret)
>                         goto out_fail;
> --
> 2.34.1
>