linux-kernel - Re: [PATCH 5/7] cpufreq: Move the check of cpufreq_driver->get into cpufreq_verify_current

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Message-ID: <3c51a0b3-9027-4397-9912-8c7635989dc6@huawei.com>
Date: Fri, 4 Jul 2025 17:16:13 +0800
From: "zhenglifeng (A)" <zhenglifeng1@...wei.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
CC: <viresh.kumar@...aro.org>, <ionela.voinescu@....com>,
	<linux-kernel@...r.kernel.org>, <linux-pm@...r.kernel.org>,
	<linuxarm@...wei.com>, <jonathan.cameron@...wei.com>,
	<zhanjie9@...ilicon.com>, <lihuisong@...wei.com>, <yubowen8@...wei.com>
Subject: Re: [PATCH 5/7] cpufreq: Move the check of cpufreq_driver->get into
 cpufreq_verify_current_freq()

On 2025/6/23 23:35, Rafael J. Wysocki wrote:

> On Mon, Jun 23, 2025 at 3:34 PM Lifeng Zheng <zhenglifeng1@...wei.com> wrote:
>>
>> Move the check of cpufreq_driver->get into cpufreq_verify_current_freq() in
>> case of calling it without check.
>>
>> Signed-off-by: Lifeng Zheng <zhenglifeng1@...wei.com>
>> ---
>>  drivers/cpufreq/cpufreq.c | 11 +++++------
>>  1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
>> index c4891bf5dc84..9b2578b905a5 100644
>> --- a/drivers/cpufreq/cpufreq.c
>> +++ b/drivers/cpufreq/cpufreq.c
>> @@ -1800,6 +1800,9 @@ static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, b
>>  {
>>         unsigned int new_freq;
>>
>> +       if (!cpufreq_driver->get)
>> +               return 0;
>> +
> 
> This will duplicate the check in cpufreq_policy_refresh(), won't it?

Yes, the check will duplicate but I think it's OK. If remove the check in
cpufreq_policy_refresh(), the logic will be changed.

> 
>>         new_freq = cpufreq_driver->get(policy->cpu);
>>         if (!new_freq)
>>                 return 0;
>> @@ -1922,10 +1925,7 @@ unsigned int cpufreq_get(unsigned int cpu)
>>
>>         guard(cpufreq_policy_read)(policy);
>>
>> -       if (cpufreq_driver->get)
>> -               return __cpufreq_get(policy);
>> -
>> -       return 0;
>> +       return __cpufreq_get(policy);
>>  }
>>  EXPORT_SYMBOL(cpufreq_get);
>>
>> @@ -2479,8 +2479,7 @@ int cpufreq_start_governor(struct cpufreq_policy *policy)
>>
>>         pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
>>
>> -       if (cpufreq_driver->get)
>> -               cpufreq_verify_current_freq(policy, false);
>> +       cpufreq_verify_current_freq(policy, false);
>>
>>         if (policy->governor->start) {
>>                 ret = policy->governor->start(policy);
>> --
>> 2.33.0
>>