On Wed, 28 Apr 2021 at 06:03, Markus Armbruster <arm...@redhat.com> wrote:
> For what it's worth, Damien further explained the two helpers in
> docs/devel/reset.rst:
>
> For Devices and Buses, the following helper functions exist:
>
> - ``device_cold_reset()``
> - ``bus_cold_reset()``
>
> These are simple wrappers around resettable_reset() function; they only
> cast the
> Device or Bus into an Object and pass the cold reset type. When possible
> prefer to use these functions instead of ``resettable_reset()``.
>
> I figure what's missing is guidance on how to transition code from
> legacy reset to multi-phase reset. Ideally with a working example
> people can study. Damien, can you help us out?
These are two separate things:
1) callsites which want to reset some other device, and currently
mostly use eg device_legacy_reset() -- the transition to be done
is to move them to use device_cold_reset(). Similarly, callsites
which currently reset a bus with qbus_reset_all() and should move
to bus_cold_reset().
2) devices which implement reset and currently do so with a
single reset method -- the transition to be done is to have
them implement however many phases of 3-phase reset they need
(1) is easier than (2) because there are many fewer callsites
trying to manually reset devices or buses than there are
devices that implement reset.
thanks
-- PMM
