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* drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy()
@ 2021-12-22 19:14 Manfred Spraul
  2021-12-30 16:23 ` Rafael J. Wysocki
  0 siblings, 1 reply; 3+ messages in thread
From: Manfred Spraul @ 2021-12-22 19:14 UTC (permalink / raw)
  To: LKML, linux-acpi, Rafael J . Wysocki , Zhang Rui, Len Brown
  Cc: 1vier1, Manfred Spraul

cpu_has_cpufreq() stores a 'struct cpufreq_policy' on the stack.
Unfortunately, with debugging options enabled, the structure can be
larger than 1024 bytes, which causes a compiler warning/error.

(actually observed: 1184 bytes).

Therefore: Switch to cpufreq_cpu_get().

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>

---
 drivers/acpi/processor_thermal.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index a3d34e3f9f94..74210d63f62c 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -53,10 +53,19 @@ static int phys_package_first_cpu(int cpu)
 
 static int cpu_has_cpufreq(unsigned int cpu)
 {
-	struct cpufreq_policy policy;
-	if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
+	struct cpufreq_policy *policy;
+	int retval;
+
+	if (!acpi_processor_cpufreq_init)
 		return 0;
-	return 1;
+
+	retval = 0;
+	policy = cpufreq_cpu_get(cpu);
+	if (policy) {
+		cpufreq_cpu_put(policy);
+		retval = 1;
+	}
+	return retval;
 }
 
 static int cpufreq_get_max_state(unsigned int cpu)
-- 
2.33.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy()
  2021-12-22 19:14 drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy() Manfred Spraul
@ 2021-12-30 16:23 ` Rafael J. Wysocki
  2021-12-30 16:47   ` Manfred Spraul
  0 siblings, 1 reply; 3+ messages in thread
From: Rafael J. Wysocki @ 2021-12-30 16:23 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: LKML, ACPI Devel Maling List, Rafael J . Wysocki, Zhang Rui,
	Len Brown, 1vier1

On Wed, Dec 22, 2021 at 8:14 PM Manfred Spraul <manfred@colorfullife.com> wrote:
>
> cpu_has_cpufreq() stores a 'struct cpufreq_policy' on the stack.
> Unfortunately, with debugging options enabled, the structure can be
> larger than 1024 bytes, which causes a compiler warning/error.
>
> (actually observed: 1184 bytes).
>
> Therefore: Switch to cpufreq_cpu_get().
>
> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
>
> ---
>  drivers/acpi/processor_thermal.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
> index a3d34e3f9f94..74210d63f62c 100644
> --- a/drivers/acpi/processor_thermal.c
> +++ b/drivers/acpi/processor_thermal.c
> @@ -53,10 +53,19 @@ static int phys_package_first_cpu(int cpu)
>
>  static int cpu_has_cpufreq(unsigned int cpu)
>  {
> -       struct cpufreq_policy policy;
> -       if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
> +       struct cpufreq_policy *policy;
> +       int retval;

Why is this needed?

> +
> +       if (!acpi_processor_cpufreq_init)
>                 return 0;
> -       return 1;
> +
> +       retval = 0;
> +       policy = cpufreq_cpu_get(cpu);
> +       if (policy) {
> +               cpufreq_cpu_put(policy);

return 1;

> +               retval = 1;
> +       }
> +       return retval;

return 0;

>  }
>
>  static int cpufreq_get_max_state(unsigned int cpu)
> --
> 2.33.1
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy()
  2021-12-30 16:23 ` Rafael J. Wysocki
@ 2021-12-30 16:47   ` Manfred Spraul
  0 siblings, 0 replies; 3+ messages in thread
From: Manfred Spraul @ 2021-12-30 16:47 UTC (permalink / raw)
  To: Rafael J. Wysocki
  Cc: LKML, ACPI Devel Maling List, Zhang Rui, Len Brown, 1vier1

[-- Attachment #1: Type: text/plain, Size: 1653 bytes --]

Hi Rafael,

On 12/30/21 17:23, Rafael J. Wysocki wrote:
> On Wed, Dec 22, 2021 at 8:14 PM Manfred Spraul <manfred@colorfullife.com> wrote:
>> cpu_has_cpufreq() stores a 'struct cpufreq_policy' on the stack.
>> Unfortunately, with debugging options enabled, the structure can be
>> larger than 1024 bytes, which causes a compiler warning/error.
>>
>> (actually observed: 1184 bytes).
>>
>> Therefore: Switch to cpufreq_cpu_get().
>>
>> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
>>
>> ---
>>   drivers/acpi/processor_thermal.c | 15 ++++++++++++---
>>   1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
>> index a3d34e3f9f94..74210d63f62c 100644
>> --- a/drivers/acpi/processor_thermal.c
>> +++ b/drivers/acpi/processor_thermal.c
>> @@ -53,10 +53,19 @@ static int phys_package_first_cpu(int cpu)
>>
>>   static int cpu_has_cpufreq(unsigned int cpu)
>>   {
>> -       struct cpufreq_policy policy;
>> -       if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
>> +       struct cpufreq_policy *policy;
>> +       int retval;
> Why is this needed?
You are right, this can be simplified. Updated patch is attached.
>> +
>> +       if (!acpi_processor_cpufreq_init)
>>                  return 0;
>> -       return 1;
>> +
>> +       retval = 0;
>> +       policy = cpufreq_cpu_get(cpu);
>> +       if (policy) {
>> +               cpufreq_cpu_put(policy);
> return 1;
>
>> +               retval = 1;
>> +       }
>> +       return retval;
> return 0;
>
>>   }
>>
>>   static int cpufreq_get_max_state(unsigned int cpu)
>> --
>> 2.33.1
>>

[-- Attachment #2: 0001-drivers-acpi-processor_thermal.c-avoid-cpufreq_get_p.patch --]
[-- Type: text/x-patch, Size: 1363 bytes --]

From b6a988751d93692026b62531f0b55a7fe69b1092 Mon Sep 17 00:00:00 2001
From: Manfred Spraul <manfred@colorfullife.com>
Date: Wed, 22 Dec 2021 15:09:31 +0100
Subject: [PATCH] drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy()

cpu_has_cpufreq() stores a 'struct cpufreq_policy' on the stack.
Unfortunately, with debugging options enabled, the structure can be
larger than 1024 bytes, which causes a compiler warning/error.

(actually observed: 1184 bytes).

Therefore: Switch to cpufreq_cpu_get().

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 drivers/acpi/processor_thermal.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index a3d34e3f9f94..d8b2dfcd59b5 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -53,10 +53,17 @@ static int phys_package_first_cpu(int cpu)
 
 static int cpu_has_cpufreq(unsigned int cpu)
 {
-	struct cpufreq_policy policy;
-	if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
+	struct cpufreq_policy *policy;
+
+	if (!acpi_processor_cpufreq_init)
 		return 0;
-	return 1;
+
+	policy = cpufreq_cpu_get(cpu);
+	if (policy) {
+		cpufreq_cpu_put(policy);
+		return 1;
+	}
+	return 0;
 }
 
 static int cpufreq_get_max_state(unsigned int cpu)
-- 
2.33.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-12-30 16:47 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-12-22 19:14 drivers/acpi/processor_thermal.c: avoid cpufreq_get_policy() Manfred Spraul
2021-12-30 16:23 ` Rafael J. Wysocki
2021-12-30 16:47   ` Manfred Spraul

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