Re: [PATCH v4 08/20] ACPI: platform_profile: Use `scoped_cond_guard`

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

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On Tue, 5 Nov 2024, Mario Limonciello wrote:

> Migrate away from using an interruptible mutex to scoped_cond_guard
> in all functions.
> 
> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/acpi/platform_profile.c | 114 ++++++++++++--------------------
>  1 file changed, 44 insertions(+), 70 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 4454c4a903c8f..fd1c4e9dccf0a 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -27,25 +27,21 @@ static ssize_t platform_profile_choices_show(struct device *dev,
>  					char *buf)
>  {
>  	int len = 0;
> -	int err, i;
> -
> -	err = mutex_lock_interruptible(&profile_lock);
> -	if (err)
> -		return err;
> -
> -	if (!cur_profile) {
> -		mutex_unlock(&profile_lock);
> -		return -ENODEV;
> -	}
> -
> -	for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
> -		if (len == 0)
> -			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
> -		else
> -			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
> +	int i;
> +
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		if (!cur_profile)
> +			return -ENODEV;
> +
> +		for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
> +			if (len == 0)
> +				len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
> +			else
> +				len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
> +		}
>  	}
>  	len += sysfs_emit_at(buf, len, "\n");
> -	mutex_unlock(&profile_lock);
> +
>  	return len;
>  }
>  
> @@ -56,20 +52,15 @@ static ssize_t platform_profile_show(struct device *dev,
>  	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
>  	int err;
>  
> -	err = mutex_lock_interruptible(&profile_lock);
> -	if (err)
> -		return err;
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		if (!cur_profile)
> +			return -ENODEV;
>  
> -	if (!cur_profile) {
> -		mutex_unlock(&profile_lock);
> -		return -ENODEV;
> +		err = cur_profile->profile_get(cur_profile, &profile);
> +		if (err)
> +			return err;
>  	}
>  
> -	err = cur_profile->profile_get(cur_profile, &profile);
> -	mutex_unlock(&profile_lock);
> -	if (err)
> -		return err;
> -
>  	/* Check that profile is valid index */
>  	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
>  		return -EIO;
> @@ -88,28 +79,20 @@ static ssize_t platform_profile_store(struct device *dev,
>  	if (i < 0)
>  		return -EINVAL;
>  
> -	err = mutex_lock_interruptible(&profile_lock);
> -	if (err)
> -		return err;
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		if (!cur_profile)
> +			return -ENODEV;
>  
> -	if (!cur_profile) {
> -		mutex_unlock(&profile_lock);
> -		return -ENODEV;
> -	}
> +		/* Check that platform supports this profile choice */
> +		if (!test_bit(i, cur_profile->choices))
> +			return -EOPNOTSUPP;
>  
> -	/* Check that platform supports this profile choice */
> -	if (!test_bit(i, cur_profile->choices)) {
> -		mutex_unlock(&profile_lock);
> -		return -EOPNOTSUPP;
> +		err = cur_profile->profile_set(cur_profile, i);
> +		if (err)
> +			return err;
>  	}
>  
> -	err = cur_profile->profile_set(cur_profile, i);
> -	if (!err)
> -		sysfs_notify(acpi_kobj, NULL, "platform_profile");
> -
> -	mutex_unlock(&profile_lock);
> -	if (err)
> -		return err;
> +	sysfs_notify(acpi_kobj, NULL, "platform_profile");

Hi Mario,

While I think it's fine, could you please mention about this move outside 
of the lock in the commit message.

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

--
 i.

>  	return count;
>  }
>  
> @@ -140,36 +123,27 @@ int platform_profile_cycle(void)
>  	enum platform_profile_option next;
>  	int err;
>  
> -	err = mutex_lock_interruptible(&profile_lock);
> -	if (err)
> -		return err;
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> +		if (!cur_profile)
> +			return -ENODEV;
>  
> -	if (!cur_profile) {
> -		mutex_unlock(&profile_lock);
> -		return -ENODEV;
> -	}
> +		err = cur_profile->profile_get(cur_profile, &profile);
> +		if (err)
> +			return err;
>  
> -	err = cur_profile->profile_get(cur_profile, &profile);
> -	if (err) {
> -		mutex_unlock(&profile_lock);
> -		return err;
> -	}
> +		next = find_next_bit_wrap(cur_profile->choices, PLATFORM_PROFILE_LAST,
> +					  profile + 1);
>  
> -	next = find_next_bit_wrap(cur_profile->choices, PLATFORM_PROFILE_LAST,
> -				  profile + 1);
> +		if (WARN_ON(next == PLATFORM_PROFILE_LAST))
> +			return -EINVAL;
>  
> -	if (WARN_ON(next == PLATFORM_PROFILE_LAST)) {
> -		mutex_unlock(&profile_lock);
> -		return -EINVAL;
> +		err = cur_profile->profile_set(cur_profile, next);
> +		if (err)
> +			return err;
>  	}
>  
> -	err = cur_profile->profile_set(cur_profile, next);
> -	mutex_unlock(&profile_lock);
> -
> -	if (!err)
> -		sysfs_notify(acpi_kobj, NULL, "platform_profile");
> -
> -	return err;
> +	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> +	return 0;
>  }
>  EXPORT_SYMBOL_GPL(platform_profile_cycle);
>  
>