Re: [PATCH v2] arm64: move efi_reboot to restart handler

[Alexander Sverdlin]

Hello Mark, Ard,

On 01/02/2022 14:58, Mark Rutland wrote:
>> You could argue that restart handlers were not created for that but they
>> suit this purpose ideally and it wouldn't make much sense (in my
>> opinion) to add yet another notifier chain that would run before reset
>> notifiers, for code that is not supposed to reset the whole system and
>> this is exacly what I would have to do if efi_reboot() is forced to be
>> called before all handlers.
> 
> As above, I think that's just using the wrong interface, and the reboot
> notifier mechanism *already* exists, so I'm really confused here.
> 
> Have I misunderstood what you're trying to achieve?
> 
> Is there some problem with the reboot notifier mechanism that I am unaware of?
> e.g. do we bypass them in some case where you think they're needed?
> 
> Are you simply unaware of reboot notifiers?

Could you please check the simple case of pwrseq_emmc.c?

While that's currently the only example of this kind upstream I can imagine
further use-cases, especially in storage area like above.

Would you suggest it's illegal usage of register_restart_handler()?
Do we need to fix pwrseq_emmc.c by introducing new atomic notifier chain
which will be called before restart handlers, so that it works on
emergency_restart()?

-- 
Best regards,
Alexander Sverdlin.