Re: [PATCH v9 17/22] ACPI: platform_profile: Make sure all profile handlers agree on profile

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

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On Sun, 1 Dec 2024, Mario Limonciello wrote:

> If for any reason multiple profile handlers don't agree on the profile
> return the custom profile.
> 
> Reviewed-by: Armin Wolf <W_Armin@gmx.de>
> Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/acpi/platform_profile.c | 119 ++++++++++++++++++++++++++------
>  1 file changed, 96 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index a9cd13c5fd39b..d5f0679d59d50 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -66,6 +66,22 @@ static int _store_class_profile(struct device *dev, void *data)
>  	return handler->profile_set(handler, *bit);
>  }
>  
> +/**
> + * _notify_class_profile - Notify the class device of a profile change
> + * @dev: The class device
> + * @data: Unused
> + */
> +static int _notify_class_profile(struct device *dev, void *data)
> +{
> +	struct platform_profile_handler *handler = dev_get_drvdata(dev);
> +
> +	lockdep_assert_held(&profile_lock);
> +	sysfs_notify(&handler->class_dev->kobj, NULL, "profile");
> +	kobject_uevent(&handler->class_dev->kobj, KOBJ_CHANGE);
> +
> +	return 0;
> +}
> +
>  /**
>   * get_class_profile - Show the current profile for a class device
>   * @dev: The class device
> @@ -246,51 +262,108 @@ static ssize_t platform_profile_choices_show(struct device *dev,
>  	return _commmon_choices_show(aggregate, buf);
>  }
>  
> +/**
> + * _aggregate_profiles - Aggregate the profiles for legacy sysfs interface
> + * @dev: The device
> + * @data: The profile to return

Please leave an empty row after args (obviously with the * continuation). 
Check all kerneldocs in the series for this.

> + * Return: 0 on success, -errno on failure
> + */
> +static int _aggregate_profiles(struct device *dev, void *data)
> +{
> +	enum platform_profile_option *profile = data;
> +	enum platform_profile_option val;
> +	int err;
> +
> +	err = get_class_profile(dev, &val);
> +	if (err)
> +		return err;
> +
> +	if (*profile != PLATFORM_PROFILE_LAST && *profile != val)
> +		*profile = PLATFORM_PROFILE_CUSTOM;
> +	else
> +		*profile = val;
> +
> +	return 0;
> +}
> +
> +/**
> + * _store_and_notify - Atomically store and notify a class from legacy sysfs interface

I'm a bit unsure what "atomically" means in this context. If it relates to 
_store_class_profile() only, that function didn't use "atomically" in its 
kerneldoc.

> + * @dev: The device
> + * @data: The profile to return
> + * Return: 0 on success, -errno on failure
> + */
> +static int _store_and_notify(struct device *dev, void *data)
> +{
> +	enum platform_profile_option *profile = data;
> +	int err;
> +
> +	err = _store_class_profile(dev, profile);
> +	if (err)
> +		return err;
> +	return _notify_class_profile(dev, NULL);
> +}
> +
> +/**
> + * platform_profile_show - Show the current profile for legacy sysfs interface
> + * @dev: The device
> + * @attr: The attribute
> + * @buf: The buffer to write to
> + * Return: The number of bytes written
> + */
>  static ssize_t platform_profile_show(struct device *dev,
> -					struct device_attribute *attr,
> -					char *buf)
> +				     struct device_attribute *attr,
> +				     char *buf)
>  {
> -	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
> +	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
>  	int err;
>  
>  	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> -		if (!cur_profile)
> -			return -ENODEV;
> -
> -		err = cur_profile->profile_get(cur_profile, &profile);
> +		err = class_for_each_device(&platform_profile_class, NULL,
> +					    &profile, _aggregate_profiles);
>  		if (err)
>  			return err;
>  	}
>  
> -	/* Check that profile is valid index */
> -	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
> -		return -EIO;
> +	/* no profile handler registered any more */
> +	if (profile == PLATFORM_PROFILE_LAST)
> +		return -EINVAL;
>  
>  	return sysfs_emit(buf, "%s\n", profile_names[profile]);
>  }
>  
> +/**
> + * platform_profile_store - Set the profile for legacy sysfs interface
> + * @dev: The device
> + * @attr: The attribute
> + * @buf: The buffer to read from
> + * @count: The number of bytes to read
> + * Return: The number of bytes read
> + */
>  static ssize_t platform_profile_store(struct device *dev,
> -			    struct device_attribute *attr,
> -			    const char *buf, size_t count)
> +				      struct device_attribute *attr,
> +				      const char *buf, size_t count)
>  {
> -	int err, i;
> +	unsigned long choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
> +	int ret;
> +	int i;
>  
>  	/* Scan for a matching profile */
>  	i = sysfs_match_string(profile_names, buf);
> -	if (i < 0)
> +	if (i < 0 || i == PLATFORM_PROFILE_CUSTOM)
>  		return -EINVAL;
> -
> +	set_bit(PLATFORM_PROFILE_LAST, choices);
>  	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> -		if (!cur_profile)
> -			return -ENODEV;
> -
> -		/* Check that platform supports this profile choice */
> -		if (!test_bit(i, cur_profile->choices))
> +		ret = class_for_each_device(&platform_profile_class, NULL,
> +					    choices, _aggregate_choices);
> +		if (ret)
> +			return ret;
> +		if (!test_bit(i, choices))
>  			return -EOPNOTSUPP;
>  
> -		err = cur_profile->profile_set(cur_profile, i);
> -		if (err)
> -			return err;
> +		ret = class_for_each_device(&platform_profile_class, NULL, &i,
> +					    _store_and_notify);
> +		if (ret)
> +			return ret;
>  	}
>  
>  	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> 

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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