Re: [PATCH v3 16/22] ACPI: platform_profile: Set profile for all registered handlers

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

On Wed, 30 Oct 2024, Mario Limonciello wrote:

> If multiple platform profile handlers have been registered then when
> setting a profile verify that all profile handlers support the requested
> profile and set it to each handler.
> 
> If this fails for any given handler, revert all profile handlers back to
> balanced and log an error into the kernel ring buffer.
> 
> Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/acpi/platform_profile.c | 25 ++++++++++++++++++++-----
>  1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index 90cbc0de4d5bc..c2bb325ba531c 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -99,6 +99,8 @@ static ssize_t platform_profile_store(struct device *dev,
>  			    struct device_attribute *attr,
>  			    const char *buf, size_t count)
>  {
> +	struct platform_profile_handler *handler;
> +	unsigned long choices;
>  	int err, i;
>  
>  	/* Scan for a matching profile */
> @@ -107,16 +109,29 @@ static ssize_t platform_profile_store(struct device *dev,
>  		return -EINVAL;
>  
>  	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
> -		if (!cur_profile)
> +		if (!platform_profile_is_registered())
>  			return -ENODEV;
>  
> -		/* Check that platform supports this profile choice */
> -		if (!test_bit(i, cur_profile->choices))
> +		/* Check that all handlers support this profile choice */
> +		choices = platform_profile_get_choices();
> +		if (!test_bit(i, &choices))
>  			return -EOPNOTSUPP;
>  
> -		err = cur_profile->profile_set(cur_profile, i);
> -		if (err)
> +		list_for_each_entry(handler, &platform_profile_handler_list, list) {
> +			err = handler->profile_set(handler, i);
> +			if (err) {
> +				pr_err("Failed to set profile for handler %s\n", handler->name);
> +				break;
> +			}
> +		}
> +		if (err) {
> +			list_for_each_entry_continue_reverse(handler, &platform_profile_handler_list, list) {

Too long line.

This looks an error rollback though so instead of break inside the loop 
you could goto into a label at the end of the function and have much less 
indentation to begin with.

> +				if (handler->profile_set(handler, PLATFORM_PROFILE_BALANCED))
> +					pr_err("Failed to revert profile for handler %s\n",
> +					       handler->name);
> +			}
>  			return err;
> +		}
>  	}
>  
>  	sysfs_notify(acpi_kobj, NULL, "platform_profile");
> 

-- 
 i.