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

Shivendra Pratap shivendra.pratap at oss.qualcomm.com
Thu Jul 23 06:09:11 PDT 2026



On 22-07-2026 13:10, Pavan Kondeti wrote:
> 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 <shivendra.pratap at oss.qualcomm.com>
>> @@ -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.

so something like a struct reboot_mode_driver should have a member
with list of predefined_modes and this member will be owned by calling 
driver?

> 
> 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.

sure can try to align this using above approach.

thanks,
Shivendra



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