[PATCH v2 08/11] accel/rocket: restore the NPU clock boot rate before powering the cores down

[Igor Paunovic]

On the shutdown question from the Sashiko review of this patch:

The gap is real, but it predates this patch. The driver in drm-misc-next
has no .shutdown callback at all, so a reboot or kexec with a job in
flight already leaves the cores running today. The callback added here
takes the devfreq device down and puts the clock back to its boot rate;
it does not stop, drain or reset the cores.

Quiescing the cores on shutdown (stopping the schedulers and resetting
the cores through rocket_core_reset()) is part of the same teardown work
as the use-after-free under "Not done" in the cover letter, where a core
is unbound while clients submit: both need the driver to stop its
schedulers and cores while files are still open. I would rather fix
both in one follow-up, once Tomeu has said which way he wants the
teardown to go.

Igor