Re: [PATCH v23 03/13] power: reset: reboot-mode: Add support for predefined reboot modes

On Tue, Jul 14, 2026 at 10:46:31PM +0530, Shivendra Pratap wrote:
> reboot-mode based drivers can define a reboot-mode by adding it under
> the reboot-mode node in device tree. This limits such drivers, to define
> any predefined reboot-modes statically within the driver and creates a
> dependency on device-tree.
> 
> Extend the reboot-mode framework to handle predefined modes alongside
> those defined in device tree. Drivers can now define their own
> reboot-modes and register them via the framework. A centralized init
> call has been added to the reboot-mode framework and adopted by
> existing drivers. This ensures driver state is initialized together
> with predefined modes.
> 
> Signed-off-by: Shivendra Pratap <[email protected]>
> @@ -195,35 +264,17 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
>  			continue;
>  		}
>  
> -		info = kzalloc(sizeof(*info), GFP_KERNEL);
> -		if (!info) {
> -			ret = -ENOMEM;
> -			goto error;
> -		}
> -
> -		if (!memchr_inv(magic, 0, count * sizeof(u32))) {
> -			pr_debug("reboot mode %s with zero magic values\n", prop->name);
> -			info->count = -1;
> -		} else {
> -			memcpy(info->magic, magic, count * sizeof(u32));
> -			info->count = count;
> -		}
> -
> -		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
> -		if (!info->mode) {
> -			ret =  -ENOMEM;
> -			goto error;
> -		} else if (info->mode[0] == '\0') {
> -			kfree_const(info->mode);
> -			ret = -EINVAL;
> -			pr_err("invalid mode name(%s): too short!\n", prop->name);
> +		info = reboot_mode_create_info(prop->name + len, magic, count);
> +		if (IS_ERR(info)) {
> +			ret = PTR_ERR(info);
>  			goto error;
>  		}
>  
>  		list_add_tail(&info->list, &reboot->head);
> -		info = NULL;
>  	}
>  
> +predefined_modes:
> +	list_splice_tail_init(&reboot->predefined_modes, &reboot->head);
>  	reboot->reboot_notifier.notifier_call = reboot_mode_notify;
>  	register_reboot_notifier(&reboot->reboot_notifier);
>  

This splice here makes me ask why we need separate API for registering
pre-defined reboot modes? why not extend `struct reboot_mode_driver` to
pass on the pre-defined modes and let `reboot_mode_register()` take care
of both OF & pre-defined modes. 

The semantics of `reboot_mode_reset_predefined_modes()` is very
confusing. It is not clear if any client driver needs to really call
before unregistering? The unregister it self is cleaning up these
pre-defined modes since they are spliced.

Thanks,
Pavan