Re: [PATCH v5 12/20] ACPI: platform_profile: Add profile attribute for class interface

[Armin Wolf <W_Armin@xxxxxx>]

Am 07.11.24 um 07:02 schrieb Mario Limonciello:

> Reading and writing the `profile` sysfs file will use the callbacks for
> the platform profile handler to read or set the given profile.
>
> Tested-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> v5:
>   * Drop recovery flow
>   * Don't get profile before setting (not needed)
>   * Simplify casting for call to _store_class_profile()
>   * Only notify legacy interface of changes
>   * Adjust mutex use
> ---
>   drivers/acpi/platform_profile.c | 110 ++++++++++++++++++++++++++++++++
>   1 file changed, 110 insertions(+)
>
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 5e0bb91c5f451..35e0e8f666072 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -65,6 +65,62 @@ static int _get_class_choices(struct device *dev, unsigned long *choices)
>   	return 0;
>   }
>
> +/**
> + * _store_class_profile - Set the profile for a class device
> + * @dev: The class device
> + * @data: The profile to set
> + */
> +static int _store_class_profile(struct device *dev, void *data)
> +{
> +	struct platform_profile_handler *handler;
> +	unsigned long choices;
> +	int *i = (int *)data;
> +	int err;
> +
> +	err = _get_class_choices(dev, &choices);
> +	if (err)
> +		return err;
> +
> +	lockdep_assert_held(&profile_lock);
> +	if (!test_bit(*i, &choices))
> +		return -EOPNOTSUPP;
> +
> +	handler = dev_get_drvdata(dev);
> +	err = handler->profile_set(handler, *i);
> +	if (err)
> +		return err;
> +
> +	return err ? err : 0;

Please just return 0 here.

> +}
> +
> +/**
> + * get_class_profile - Show the current profile for a class device
> + * @dev: The class device
> + * @profile: The profile to return
> + * Return: 0 on success, -errno on failure
> + */
> +static int get_class_profile(struct device *dev,
> +			     enum platform_profile_option *profile)
> +{
> +	struct platform_profile_handler *handler;
> +	enum platform_profile_option val;
> +	int err;
> +
> +	lockdep_assert_held(&profile_lock);
> +	handler = dev_get_drvdata(dev);
> +	err = handler->profile_get(handler, &val);
> +	if (err) {
> +		pr_err("Failed to get profile for handler %s\n", handler->name);
> +		return err;
> +	}
> +
> +	if (WARN_ON(val >= PLATFORM_PROFILE_LAST))
> +		return -EINVAL;
> +	*profile = val;
> +
> +	return 0;
> +}
> +
>   /**
>    * name_show - Show the name of the profile handler
>    * @dev: The device
> @@ -106,12 +162,66 @@ static ssize_t choices_show(struct device *dev,
>   	return _commmon_choices_show(choices, buf);
>   }
>
> +/**
> + * profile_show - Show the current profile for a class device
> + * @dev: The device
> + * @attr: The attribute
> + * @buf: The buffer to write to
> + * Return: The number of bytes written
> + */
> +static ssize_t profile_show(struct device *dev,
> +			    struct device_attribute *attr,
> +			    char *buf)
> +{
> +	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
> +	int err;
> +
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		err = get_class_profile(dev, &profile);
> +		if (err)
> +			return err;
> +	}
> +
> +	return sysfs_emit(buf, "%s\n", profile_names[profile]);

AFAIK we do not need to take the mutex here, since querying the current platform profile
should not change any state.

Thanks,
Armin Wolf

> +}
> +
> +/**
> + * profile_store - Set the profile for a class device
> + * @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 profile_store(struct device *dev,
> +			     struct device_attribute *attr,
> +			     const char *buf, size_t count)
> +{
> +	int i, ret;
> +
> +	i = sysfs_match_string(profile_names, buf);
> +	if (i < 0)
> +		return -EINVAL;
> +
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		ret = _store_class_profile(dev, &i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> +
> +	return count;
> +}
> +
>   static DEVICE_ATTR_RO(name);
>   static DEVICE_ATTR_RO(choices);
> +static DEVICE_ATTR_RW(profile);
>
>   static struct attribute *profile_attrs[] = {
>   	&dev_attr_name.attr,
>   	&dev_attr_choices.attr,
> +	&dev_attr_profile.attr,
>   	NULL
>   };
>   ATTRIBUTE_GROUPS(profile);