linux-kernel - Re: [PATCH 1/3] cpuidle: Add enable

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Message-ID: <11f9d333-4d18-463a-817f-d3f450d1624e@huawei.com>
Date: Thu, 15 Jan 2026 20:18:40 +0800
From: "lihuisong (C)" <lihuisong@...wei.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
CC: <lenb@...nel.org>, <linux-acpi@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <Sudeep.Holla@....com>,
	<linuxarm@...wei.com>, <jonathan.cameron@...wei.com>,
	<zhanjie9@...ilicon.com>, <zhenglifeng1@...wei.com>, <yubowen8@...wei.com>,
	<lihuisong@...wei.com>
Subject: Re: [PATCH 1/3] cpuidle: Add enable_cpuidle() interface


On 1/15/2026 3:18 AM, Rafael J. Wysocki wrote:
> On Tue, Nov 25, 2025 at 8:29 AM Huisong Li <lihuisong@...wei.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.
>> Signed-off-by: Huisong Li <lihuisong@...wei.com>
>> ---
>>   drivers/cpuidle/cpuidle.c | 5 ++++-
>>   include/linux/cpuidle.h   | 2 ++
>>   2 files changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
>> index 56132e843c99..980ddfd3d930 100644
>> --- a/drivers/cpuidle/cpuidle.c
>> +++ b/drivers/cpuidle/cpuidle.c
>> @@ -48,7 +48,10 @@ void disable_cpuidle(void)
>>   {
>>          off = 1;
>>   }
>> -
>> +void enable_cpuidle(void)
>> +{
>> +       off = 0;
>> +}
>>   bool cpuidle_not_available(struct cpuidle_driver *drv,
>>                             struct cpuidle_device *dev)
>>   {
>> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
>> index a9ee4fe55dcf..94c030748af3 100644
>> --- a/include/linux/cpuidle.h
>> +++ b/include/linux/cpuidle.h
>> @@ -168,6 +168,7 @@ struct cpuidle_driver {
>>   };
>>
>>   #ifdef CONFIG_CPU_IDLE
>> +extern void enable_cpuidle(void);
>>   extern void disable_cpuidle(void);
>>   extern bool cpuidle_not_available(struct cpuidle_driver *drv,
>>                                    struct cpuidle_device *dev);
>> @@ -203,6 +204,7 @@ extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
>>   static inline struct cpuidle_device *cpuidle_get_device(void)
>>   {return __this_cpu_read(cpuidle_devices); }
>>   #else
>> +static inline void enable_cpuidle(void) { }
>>   static inline void disable_cpuidle(void) { }
>>   static inline bool cpuidle_not_available(struct cpuidle_driver *drv,
>>                                           struct cpuidle_device *dev)
>> --
>> 2.33.0
>>