[v2] ACPI: platform_profile: Improve platform_profile_unregister

[PATCH v2] ACPI: platform_profile: Improve platform_profile_unregister

Posted by Kurt Borja 10 months, 1 week ago

Drivers usually call this method on error/exit paths and do not check
for it's return value, which is always 0 anyway, so make it void. This
is safe to do as currently all drivers use
devm_platform_profile_register().

While at it improve the style and make the function safer by checking
for IS_ERR_OR_NULL before dereferencing the device pointer.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
Hi all,

I made a little modification that I forgot in the last version.

Rafael, please tell me if you prefer different commits for this. Also
should we WARN_ON(IS_ERR_OR_NULL)?

Based on the acpi branch of the linux-pm tree.

~ Kurt

Changes in v2:
  - Get reference to pprof after checking for IS_ERR_OR_NULL(dev)
  - CC Mark Pearson (sorry!)

 drivers/acpi/platform_profile.c  | 19 +++++++++----------
 include/linux/platform_profile.h |  2 +-
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index fc92e43d0fe9..ed9c0cc9ea9c 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -569,24 +569,23 @@ EXPORT_SYMBOL_GPL(platform_profile_register);
 /**
  * platform_profile_remove - Unregisters a platform profile class device
  * @dev: Class device
- *
- * Return: 0
  */
-int platform_profile_remove(struct device *dev)
+void platform_profile_remove(struct device *dev)
 {
-	struct platform_profile_handler *pprof = to_pprof_handler(dev);
-	int id;
+	struct platform_profile_handler *pprof;
+
+	if (IS_ERR_OR_NULL(dev))
+		return;
+
+	pprof = to_pprof_handler(dev);
+
 	guard(mutex)(&profile_lock);
 
-	id = pprof->minor;
+	ida_free(&platform_profile_ida, pprof->minor);
 	device_unregister(&pprof->dev);
-	ida_free(&platform_profile_ida, id);
 
 	sysfs_notify(acpi_kobj, NULL, "platform_profile");
-
 	sysfs_update_group(acpi_kobj, &platform_profile_group);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(platform_profile_remove);
 
diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
index 8ab5b0e8eb2c..d5499eca9e1d 100644
--- a/include/linux/platform_profile.h
+++ b/include/linux/platform_profile.h
@@ -47,7 +47,7 @@ struct platform_profile_ops {
 struct device *platform_profile_register(struct device *dev, const char *name,
 					 void *drvdata,
 					 const struct platform_profile_ops *ops);
-int platform_profile_remove(struct device *dev);
+void platform_profile_remove(struct device *dev);
 struct device *devm_platform_profile_register(struct device *dev, const char *name,
 					      void *drvdata,
 					      const struct platform_profile_ops *ops);

base-commit: 3e3e377dd1f300bbdd230533686ce9c9f4f8a90d
-- 
2.48.1

Re: [PATCH v2] ACPI: platform_profile: Improve platform_profile_unregister

Posted by Rafael J. Wysocki 10 months ago

On Wed, Feb 12, 2025 at 8:03 PM Kurt Borja <kuurtb@gmail.com> wrote:
>
> Drivers usually call this method on error/exit paths and do not check
> for it's return value, which is always 0 anyway, so make it void. This
> is safe to do as currently all drivers use
> devm_platform_profile_register().
>
> While at it improve the style and make the function safer by checking
> for IS_ERR_OR_NULL before dereferencing the device pointer.
>
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
> Hi all,
>
> I made a little modification that I forgot in the last version.
>
> Rafael, please tell me if you prefer different commits for this. Also
> should we WARN_ON(IS_ERR_OR_NULL)?
>
> Based on the acpi branch of the linux-pm tree.
>
> ~ Kurt
>
> Changes in v2:
>   - Get reference to pprof after checking for IS_ERR_OR_NULL(dev)
>   - CC Mark Pearson (sorry!)
>
>  drivers/acpi/platform_profile.c  | 19 +++++++++----------
>  include/linux/platform_profile.h |  2 +-
>  2 files changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index fc92e43d0fe9..ed9c0cc9ea9c 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -569,24 +569,23 @@ EXPORT_SYMBOL_GPL(platform_profile_register);
>  /**
>   * platform_profile_remove - Unregisters a platform profile class device
>   * @dev: Class device
> - *
> - * Return: 0
>   */
> -int platform_profile_remove(struct device *dev)
> +void platform_profile_remove(struct device *dev)
>  {
> -       struct platform_profile_handler *pprof = to_pprof_handler(dev);
> -       int id;
> +       struct platform_profile_handler *pprof;
> +
> +       if (IS_ERR_OR_NULL(dev))
> +               return;
> +
> +       pprof = to_pprof_handler(dev);
> +
>         guard(mutex)(&profile_lock);
>
> -       id = pprof->minor;
> +       ida_free(&platform_profile_ida, pprof->minor);
>         device_unregister(&pprof->dev);
> -       ida_free(&platform_profile_ida, id);
>
>         sysfs_notify(acpi_kobj, NULL, "platform_profile");
> -
>         sysfs_update_group(acpi_kobj, &platform_profile_group);
> -
> -       return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_remove);
>
> diff --git a/include/linux/platform_profile.h b/include/linux/platform_profile.h
> index 8ab5b0e8eb2c..d5499eca9e1d 100644
> --- a/include/linux/platform_profile.h
> +++ b/include/linux/platform_profile.h
> @@ -47,7 +47,7 @@ struct platform_profile_ops {
>  struct device *platform_profile_register(struct device *dev, const char *name,
>                                          void *drvdata,
>                                          const struct platform_profile_ops *ops);
> -int platform_profile_remove(struct device *dev);
> +void platform_profile_remove(struct device *dev);
>  struct device *devm_platform_profile_register(struct device *dev, const char *name,
>                                               void *drvdata,
>                                               const struct platform_profile_ops *ops);
>
> base-commit: 3e3e377dd1f300bbdd230533686ce9c9f4f8a90d
> --

Applied as 6.15 material with minor edits in the changelog, thanks!

Re: [PATCH v2] ACPI: platform_profile: Improve platform_profile_unregister

Posted by Mark Pearson 10 months, 1 week ago

Hi Kurt

On Wed, Feb 12, 2025, at 2:03 PM, Kurt Borja wrote:
> Drivers usually call this method on error/exit paths and do not check
> for it's return value, which is always 0 anyway, so make it void. This
> is safe to do as currently all drivers use
> devm_platform_profile_register().
>
I was worried I had mucked that up with the revert done in thinkpad_acpi? But it's not checking the return there so I think it's fine

> While at it improve the style and make the function safer by checking
> for IS_ERR_OR_NULL before dereferencing the device pointer.
>
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
> Hi all,
>
> I made a little modification that I forgot in the last version.
>
> Rafael, please tell me if you prefer different commits for this. Also
> should we WARN_ON(IS_ERR_OR_NULL)?
>
> Based on the acpi branch of the linux-pm tree.
>
> ~ Kurt
>
> Changes in v2:
>   - Get reference to pprof after checking for IS_ERR_OR_NULL(dev)
>   - CC Mark Pearson (sorry!)
>
>  drivers/acpi/platform_profile.c  | 19 +++++++++----------
>  include/linux/platform_profile.h |  2 +-
>  2 files changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index fc92e43d0fe9..ed9c0cc9ea9c 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -569,24 +569,23 @@ EXPORT_SYMBOL_GPL(platform_profile_register);
>  /**
>   * platform_profile_remove - Unregisters a platform profile class device
>   * @dev: Class device
> - *
> - * Return: 0
>   */
> -int platform_profile_remove(struct device *dev)
> +void platform_profile_remove(struct device *dev)
>  {
> -	struct platform_profile_handler *pprof = to_pprof_handler(dev);
> -	int id;
> +	struct platform_profile_handler *pprof;
> +
> +	if (IS_ERR_OR_NULL(dev))
> +		return;
> +
> +	pprof = to_pprof_handler(dev);
> +
>  	guard(mutex)(&profile_lock);
> 
> -	id = pprof->minor;
> +	ida_free(&platform_profile_ida, pprof->minor);
>  	device_unregister(&pprof->dev);
> -	ida_free(&platform_profile_ida, id);
> 
>  	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> -
>  	sysfs_update_group(acpi_kobj, &platform_profile_group);
> -
> -	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_remove);
> 
> diff --git a/include/linux/platform_profile.h 
> b/include/linux/platform_profile.h
> index 8ab5b0e8eb2c..d5499eca9e1d 100644
> --- a/include/linux/platform_profile.h
> +++ b/include/linux/platform_profile.h
> @@ -47,7 +47,7 @@ struct platform_profile_ops {
>  struct device *platform_profile_register(struct device *dev, const 
> char *name,
>  					 void *drvdata,
>  					 const struct platform_profile_ops *ops);
> -int platform_profile_remove(struct device *dev);
> +void platform_profile_remove(struct device *dev);
>  struct device *devm_platform_profile_register(struct device *dev, 
> const char *name,
>  					      void *drvdata,
>  					      const struct platform_profile_ops *ops);
>
> base-commit: 3e3e377dd1f300bbdd230533686ce9c9f4f8a90d
> -- 
> 2.48.1
Looks good to me
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Mark

Re: [PATCH v2] ACPI: platform_profile: Improve platform_profile_unregister

Posted by Kurt Borja 10 months ago

Hi Mark,

On Wed Feb 12, 2025 at 3:41 PM -05, Mark Pearson wrote:
> Hi Kurt
>
> On Wed, Feb 12, 2025, at 2:03 PM, Kurt Borja wrote:
>> Drivers usually call this method on error/exit paths and do not check
>> for it's return value, which is always 0 anyway, so make it void. This
>> is safe to do as currently all drivers use
>> devm_platform_profile_register().
>>
> I was worried I had mucked that up with the revert done in thinkpad_acpi? But it's not checking the return there so I think it's fine

Don't worry. I was aware of that :)

>
>> While at it improve the style and make the function safer by checking
>> for IS_ERR_OR_NULL before dereferencing the device pointer.
>>
>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>> ---
>> Hi all,
>>
>> I made a little modification that I forgot in the last version.
>>
>> Rafael, please tell me if you prefer different commits for this. Also
>> should we WARN_ON(IS_ERR_OR_NULL)?
>>
>> Based on the acpi branch of the linux-pm tree.
>>
>> ~ Kurt
>>
>> Changes in v2:
>>   - Get reference to pprof after checking for IS_ERR_OR_NULL(dev)
>>   - CC Mark Pearson (sorry!)
>>
>>  drivers/acpi/platform_profile.c  | 19 +++++++++----------
>>  include/linux/platform_profile.h |  2 +-
>>  2 files changed, 10 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
>> index fc92e43d0fe9..ed9c0cc9ea9c 100644
>> --- a/drivers/acpi/platform_profile.c
>> +++ b/drivers/acpi/platform_profile.c
>> @@ -569,24 +569,23 @@ EXPORT_SYMBOL_GPL(platform_profile_register);
>>  /**
>>   * platform_profile_remove - Unregisters a platform profile class device
>>   * @dev: Class device
>> - *
>> - * Return: 0
>>   */
>> -int platform_profile_remove(struct device *dev)
>> +void platform_profile_remove(struct device *dev)
>>  {
>> -	struct platform_profile_handler *pprof = to_pprof_handler(dev);
>> -	int id;
>> +	struct platform_profile_handler *pprof;
>> +
>> +	if (IS_ERR_OR_NULL(dev))
>> +		return;
>> +
>> +	pprof = to_pprof_handler(dev);
>> +
>>  	guard(mutex)(&profile_lock);
>> 
>> -	id = pprof->minor;
>> +	ida_free(&platform_profile_ida, pprof->minor);
>>  	device_unregister(&pprof->dev);
>> -	ida_free(&platform_profile_ida, id);
>> 
>>  	sysfs_notify(acpi_kobj, NULL, "platform_profile");
>> -
>>  	sysfs_update_group(acpi_kobj, &platform_profile_group);
>> -
>> -	return 0;
>>  }
>>  EXPORT_SYMBOL_GPL(platform_profile_remove);
>> 
>> diff --git a/include/linux/platform_profile.h 
>> b/include/linux/platform_profile.h
>> index 8ab5b0e8eb2c..d5499eca9e1d 100644
>> --- a/include/linux/platform_profile.h
>> +++ b/include/linux/platform_profile.h
>> @@ -47,7 +47,7 @@ struct platform_profile_ops {
>>  struct device *platform_profile_register(struct device *dev, const 
>> char *name,
>>  					 void *drvdata,
>>  					 const struct platform_profile_ops *ops);
>> -int platform_profile_remove(struct device *dev);
>> +void platform_profile_remove(struct device *dev);
>>  struct device *devm_platform_profile_register(struct device *dev, 
>> const char *name,
>>  					      void *drvdata,
>>  					      const struct platform_profile_ops *ops);
>>
>> base-commit: 3e3e377dd1f300bbdd230533686ce9c9f4f8a90d
>> -- 
>> 2.48.1
> Looks good to me
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>

Thank you very much!

-- 
 ~ Kurt

>
> Mark