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Message-ID: <CAJZ5v0iTdgM5BBi2ysiJxfA2c=MQ0fjLsEvVct9stxomvEe=4Q@mail.gmail.com>
Date: Fri, 5 Sep 2025 22:17:26 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Zihuan Zhang <zhangzihuan@...inos.cn>
Cc: "Rafael J . wysocki" <rafael@...nel.org>, Viresh Kumar <viresh.kumar@...aro.org>,
Jonathan Cameron <jonathan.cameron@...wei.com>, 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>,
Krzysztof Kozlowski <krzk@...nel.org>, 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>,
Jani Nikula <jani.nikula@...ux.intel.com>, Rodrigo Vivi <rodrigo.vivi@...el.com>,
Tvrtko Ursulin <tursulin@...ulin.net>, David Airlie <airlied@...il.com>,
Simona Vetter <simona@...ll.ch>, Daniel Lezcano <daniel.lezcano@...nel.org>,
Sascha Hauer <s.hauer@...gutronix.de>, Shawn Guo <shawnguo@...nel.org>,
Eduardo Valentin <edubezval@...il.com>, Keerthy <j-keerthy@...com>, Ben Horgan <ben.horgan@....com>,
zhenglifeng <zhenglifeng1@...wei.com>, Zhang Rui <rui.zhang@...el.com>,
Len Brown <lenb@...nel.org>, Lukasz Luba <lukasz.luba@....com>,
Pengutronix Kernel Team <kernel@...gutronix.de>, Beata Michalska <beata.michalska@....com>,
Fabio Estevam <festevam@...il.com>, Pavel Machek <pavel@...nel.org>, Sumit Gupta <sumitg@...dia.com>,
Prasanna Kumar T S M <ptsm@...ux.microsoft.com>, Sudeep Holla <sudeep.holla@....com>,
Yicong Yang <yangyicong@...ilicon.com>, linux-pm@...r.kernel.org,
linux-acpi@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
linux-arm-kernel@...ts.infradead.org, intel-gfx@...ts.freedesktop.org,
dri-devel@...ts.freedesktop.org, imx@...ts.linux.dev,
linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 2/6] ACPI: processor: thermal: Use scope-based cleanup helper
On Fri, Sep 5, 2025 at 3:24 PM Zihuan Zhang <zhangzihuan@...inos.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@...inos.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.
> +
> + 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;
> }
> --
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