[PATCH v1 0/3] Asynchronous shutdown interface and example implementation

[Rafael J. Wysocki]

On Wed, Mar 30, 2022 at 8:25 AM Lukas Wunner <lukas at wunner.de> wrote:
>
> On Tue, Mar 29, 2022 at 08:07:51PM -0600, Keith Busch wrote:
> > Thanks, I agree we should improve shutdown times. I tried a while ago, but
> > lost track to follow up at the time. Here's the reference, fwiw, though it
> > may be out of date :):
> >
> >   http://lists.infradead.org/pipermail/linux-nvme/2014-May/000826.html
> >
> > The above solution is similiar to how probe waits on an async domain.
> > Maybe pci can schedule the async shutdown instead of relying on low-level
> > drivers so that everyone implicitly benefits instead of just nvme? I'll
> > double-check if that's reasonable, but I'll look through this series too.
>
> Using the async API seems much more reasonable than adding new callbacks.
>
> However I'd argue that it shouldn't be necessary to amend any drivers,
> this should all be doable in the driver core:  Basically a device needs
> to wait for its children and device links consumers to shutdown, apart
> from that everything should be able to run asynchronously.

Well, this is done already in the system-wide and hibernation paths.
It should be possible to implement asynchronous shutdown analogously.