linux-kernel - Re: [PATCH v4 09/10] thermal/drivers/ti-soc-thermal: Use scope-based cleanup helper

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Message-ID: <2ccca29e-4d5f-44fa-bfc8-d77c659bc9f3@kylinos.cn>
Date: Fri, 5 Sep 2025 15:54:21 +0800
From: Zihuan Zhang <zhangzihuan@...inos.cn>
To: Andreas Kemnade <andreas@...nade.info>,
 Krzysztof Kozlowski <krzk@...nel.org>
Cc: "Rafael J . wysocki" <rafael@...nel.org>,
 Viresh Kumar <viresh.kumar@...aro.org>,
 Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>,
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
 Michael Ellerman <mpe@...erman.id.au>, Alim Akhtar
 <alim.akhtar@...sung.com>, Thierry Reding <thierry.reding@...il.com>,
 MyungJoo Ham <myungjoo.ham@...sung.com>,
 Kyungmin Park <kyungmin.park@...sung.com>,
 Chanwoo Choi <cw00.choi@...sung.com>,
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Subject: Re: [PATCH v4 09/10] thermal/drivers/ti-soc-thermal: Use scope-based
 cleanup helper

在 2025/9/5 14:57, Andreas Kemnade 写道:
> Am Wed,  3 Sep 2025 21:17:32 +0800
> schrieb Zihuan Zhang <zhangzihuan@...inos.cn>:
>
>> 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@...inos.cn>
>> ---
>>   drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 13 ++++---------
>>   1 file changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> index 0cf0826b805a..37d06468913a 100644
>> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> @@ -27,7 +27,6 @@
>>   
>>   /* common data structures */
>>   struct ti_thermal_data {
>> -	struct cpufreq_policy *policy;
>>   	struct thermal_zone_device *ti_thermal;
>>   	struct thermal_zone_device *pcb_tz;
>>   	struct thermal_cooling_device *cool_dev;
>> @@ -218,6 +217,7 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
>>   {
>>   	struct ti_thermal_data *data;
>>   	struct device_node *np = bgp->dev->of_node;
>> +	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(0);
>>   
> this looks as it changes the lifecycle from the device lifetime to just
> this function...

I thought policy was only used in this function, so I moved it here.

Thanks for clarifying the lifecycle issue.

>>   	/*
>>   	 * We are assuming here that if one deploys the zone
>> @@ -234,19 +234,17 @@ int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
>>   	if (!data)
>>   		return -EINVAL;
>>   
>> -	data->policy = cpufreq_cpu_get(0);
>> -	if (!data->policy) {
>> +	if (!policy) {
>>   		pr_debug("%s: CPUFreq policy not found\n", __func__);
>>   		return -EPROBE_DEFER;
>>   	}
>>   
>>   	/* Register cooling device */
>> -	data->cool_dev = cpufreq_cooling_register(data->policy);
>> +	data->cool_dev = cpufreq_cooling_register(policy);
> and it is passed on to something living beyond this function. I see no
> _get(policy) in cpufreq_cooling_register().
> Am I missing something?

This indeed causes a problem.

Sure,  I will drop the patchset.

Thanks!

> Regards,
> Andreas