[PATCH v5 2/6] ACPI: processor: thermal: Use scope-based cleanup helper

[Zihuan Zhang]

在 2025/9/6 04:17, Rafael J. Wysocki 写道:
> On Fri, Sep 5, 2025 at 3:24 PM Zihuan Zhang <zhangzihuan at kylinos.cn> wrote:
>> Replace the manual cpufreq_cpu_put() with __free(put_cpufreq_policy)
>> annotation for policy references. This reduces the risk of reference
>> counting mistakes and aligns the code with the latest kernel style.
>>
>> No functional change intended.
>>
>> Signed-off-by: Zihuan Zhang <zhangzihuan at kylinos.cn>
>> ---
>>   drivers/acpi/processor_thermal.c | 52 +++++++++++++++++---------------
>>   1 file changed, 27 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
>> index 1219adb11ab9..460713d1414a 100644
>> --- a/drivers/acpi/processor_thermal.c
>> +++ b/drivers/acpi/processor_thermal.c
>> @@ -62,19 +62,14 @@ static int phys_package_first_cpu(int cpu)
>>          return 0;
>>   }
>>
>> -static int cpu_has_cpufreq(unsigned int cpu)
>> +static bool cpu_has_cpufreq(unsigned int cpu)
>>   {
>> -       struct cpufreq_policy *policy;
>> -
>>          if (!acpi_processor_cpufreq_init)
>>                  return 0;
>>
>> -       policy = cpufreq_cpu_get(cpu);
>> -       if (policy) {
>> -               cpufreq_cpu_put(policy);
>> -               return 1;
>> -       }
>> -       return 0;
>> +       struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
>> +
>> +       return policy != NULL;
>>   }
>>
>>   static int cpufreq_get_max_state(unsigned int cpu)
> The changes above are fine and can be sent as a separate patch.
>
>> @@ -93,12 +88,31 @@ static int cpufreq_get_cur_state(unsigned int cpu)
>>          return reduction_step(cpu);
>>   }
>>
>> +static bool cpufreq_update_thermal_limit(unsigned int cpu, struct acpi_processor *pr)
>> +{
>> +       unsigned long max_freq;
>> +       int ret;
>> +       struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
>> +
>> +       if (!policy)
>> +               return false;
>> +
>> +       max_freq = (policy->cpuinfo.max_freq *
>> +               (100 - reduction_step(cpu) * cpufreq_thermal_reduction_pctg)) / 100;
>> +
>> +       ret = freq_qos_update_request(&pr->thermal_req, max_freq);
>> +       if (ret < 0) {
>> +               pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
>> +         pr->id, ret);
>> +       }
> But this silently fixes a bug in the original code which needs to be
> documented with a Fixes: tag (and it would be better to fix the bug
> separately before the using the __free()-based cleanup TBH) and
> introduces some whitespace breakage.

Thanks!

  I’ll follow your advice and handle the Fixes tag and whitespace issues.


>> +
>> +       return true;
>> +}
>> +
>>   static int cpufreq_set_cur_state(unsigned int cpu, int state)
>>   {
>> -       struct cpufreq_policy *policy;
>>          struct acpi_processor *pr;
>> -       unsigned long max_freq;
>> -       int i, ret;
>> +       int i;
>>
>>          if (!cpu_has_cpufreq(cpu))
>>                  return 0;
>> @@ -120,20 +134,8 @@ static int cpufreq_set_cur_state(unsigned int cpu, int state)
>>                  if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
>>                          continue;
>>
>> -               policy = cpufreq_cpu_get(i);
>> -               if (!policy)
>> +               if (!cpufreq_update_thermal_limit(i, pr))
>>                          return -EINVAL;
>> -
>> -               max_freq = (policy->cpuinfo.max_freq *
>> -                           (100 - reduction_step(i) * cpufreq_thermal_reduction_pctg)) / 100;
>> -
>> -               cpufreq_cpu_put(policy);
>> -
>> -               ret = freq_qos_update_request(&pr->thermal_req, max_freq);
>> -               if (ret < 0) {
>> -                       pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
>> -                               pr->id, ret);
>> -               }
>>          }
>>          return 0;
>>   }
>> --