On Thu, 13 Apr 2023, 22:37 Dmitry Osipenko, <dmitry.osipenko@xxxxxxxxxxxxx> wrote: > Handlers must return NOTIFY_DONE or notifier_from_errno(). Sorry for > missing this previously. Thanks! AFAIU, notifier_from_errno() sets NOTIFY_STOP_MASK, which stops atomic_notifier_call_chain() immediately. So I think NOTIFY_DONE is the only valid return value for sys_off handlers, to not skip others. So I think letting sys_off_notify() [1] always return NOTIFY_DONE might be a good idea. If so, we could return a "notify return errno" (or also a "normal errno") from the handler, which is checked, but then replaced to NOTIFY_DONE, in [1]. This would enable us to have a common place to check for failed handlers. Handlers then should only return NOTIFY_DONE when they are skipped (e.g. when the requested reboot mode is not supported by the handler). Otherwise, I think ETIME, ENOSYS or ENOTSUPP might fit when the communication was successful, a possible delay awaited, but the return was still reached. What do you think? Thanks and best regards, Benjamin [1] https://elixir.bootlin.com/linux/v6.3-rc6/source/kernel/reboot.c#L327
