Re: [PATCH] kernel/reboot: add devm_register_reboot_notifier

[Andrey Smirnov]

On Wed, Mar 29, 2017 at 4:17 PM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 20 Mar 2017 10:17:53 -0700 Andrey Smirnov <andrew.smirnov@xxxxxxxxx> wrote:
>
>> Add devm_* wrapper around register_reboot_notifier to simplify device
>> specific reboot notifier registration/unregistration.
>>
>> --- a/kernel/reboot.c
>> +++ b/kernel/reboot.c
>> @@ -104,6 +104,33 @@ int unregister_reboot_notifier(struct notifier_block *nb)
>>  }
>>  EXPORT_SYMBOL(unregister_reboot_notifier);
>>
>> +static void devm_unregister_reboot_notifier(struct device *dev, void *res)
>> +{
>> +     WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res));
>> +}
>> +
>> +int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb)
>> +{
>> +     struct notifier_block **rcnb;
>> +     int ret;
>> +
>> +     rcnb = devres_alloc(devm_unregister_reboot_notifier,
>> +                         sizeof(*rcnb), GFP_KERNEL);
>> +     if (!rcnb)
>> +             return -ENOMEM;
>> +
>> +     ret = register_reboot_notifier(nb);
>> +     if (!ret) {
>> +             *rcnb = nb;
>> +             devres_add(dev, rcnb);
>> +     } else {
>> +             devres_free(rcnb);
>> +     }
>> +
>> +     return ret;
>> +}
>> +EXPORT_SYMBOL(devm_register_reboot_notifier);
>
> Seems reasonable.  Can we please have some patches which actually use
> this?

I will be submitting a serdev/watchdog driver in next couple of weeks,
I can CC you on that thread.

Thanks,
Andrey Smirnov