Re: [PATCH 1/3] cpuidle: Add enable_cpuidle() interface

["lihuisong (C)" <lihuisong@huawei.com>]

On 3/26/2026 9:39 PM, Rafael J. Wysocki wrote:
> On Thu, Mar 26, 2026 at 1:17 PM lihuisong (C) <lihuisong@huawei.com> wrote:
>> Hi Rafael,
>>
>> On 1/30/2026 9:59 AM, lihuisong (C) wrote:
>>> Hi Rafael,
>>>
>>> On 1/15/2026 8:18 PM, lihuisong (C) wrote:
>>>> On 1/15/2026 3:18 AM, Rafael J. Wysocki wrote:
>>>>> On Tue, Nov 25, 2025 at 8:29 AM Huisong Li <lihuisong@huawei.com>
>>>>> wrote:
>>>>>> The global switch of cpuidle can be turned back on in some case.
>>>>>> So add enable_cpuidle().
>>>>> No, this is not going to work.  The "off" switch only affects
>>>>> initialization AFAICS.
>>>> I think it would be work.
>>>> The cpuidle_not_available() also see the "off" on do_idle().
>>>> And cpuidle_idle_call() check this function first and then select
>>>> idle state.
>>>> Cpuidle doesn't select and enter idle state if this fuction return true.
>>> I verified that disable_cpuidle() effectively prevents all CPUs from
>>> entering any idle states and the cpuidle function is correctly
>>> restored after calling enable_cpuidle().
>>> What do you think?
>> Could you pleasetake a look atmy reply?
>> If not ok, I will drop this from my upstream list.
> Sorry, can you please remind me what problem you wanted to address
> with the help of this?
Regarding the discussion in the link[1], if driver fail to get power 
info in power notify,
the old idle states may no longer be reliable. Therefore, patch 2/3 
disables ACPI idle
via the new interface introduced in patch 1/3.

However, our discussion on whether this new interface can disable ACPI 
idle has not yet reached a conclusion.
Could you please revisit this thread? It's quite brief, and I'd 
appreciate your further input.

[1] 
https://lore.kernel.org/all/20251103084244.2654432-1-lihuisong@huawei.com