linux-kernel - Re: [PATCH v2] ACPI: platform_profile: Improve platform_profile

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Message-Id: <D7QWLKBQ69RZ.1BIAN6FNN7V9B@gmail.com>
Date: Wed, 12 Feb 2025 19:49:43 -0500
From: "Kurt Borja" <kuurtb@...il.com>
To: "Mark Pearson" <mpearson-lenovo@...ebb.ca>, "Rafael J. Wysocki"
 <rafael@...nel.org>
Cc: "Len Brown" <lenb@...nel.org>, "linux-acpi@...r.kernel.org"
 <linux-acpi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
 "Limonciello, Mario" <mario.limonciello@....com>,
 "platform-driver-x86@...r.kernel.org" <platform-driver-x86@...r.kernel.org>
Subject: Re: [PATCH v2] ACPI: platform_profile: Improve
 platform_profile_unregister

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@...il.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@...ebb.ca>

Thank you very much!

-- 
 ~ Kurt

>
> Mark