[PATCH v7 08/10] accel/rocket: add RK3576 NPU (RKNN) support

[Igor Paunovic]

Two things here, one of which I think has to be fixed before this
lands.

The first is a comment that outlived its subject. This patch adds the
following just above the PC_TASK_CON block:

  /*
   * RK3576 arms the same DPU completion as RK3588, but the interrupt
   * never reaches the GIC. The completion itself is visible in
   * INTERRUPT_RAW_STATUS, so sample that instead. The tick cap bounds
   * jobs that never raise it at all, which is the same open problem as
   * the wrong inference results.
   */

That is the v6 comment for the poll. It states the premise your cover
letter withdraws, it describes machinery this version deletes, and it
has no code under it - the next line opens the second comment block.
Left in, the driver would carry a claim that contradicts both the
commit introducing it and the register description two paragraphs
below it.

The second is placement rather than correctness. This patch also
factors the completion tail out of rocket_job_handle_irq() into
rocket_job_next_locked(). I read that as behaviour-neutral on RK3588 -
the return that used to leave handle_irq() now leaves the helper, and
scoped_guard drops the lock either way - and the numbers I posted on
1/10 bear it out. But it restructures the shared completion path in a
patch whose subject is adding RK3576, which puts a bisect in the wrong
place if it ever turns out not to be neutral. It would sit more
naturally in 1/10, which already touches that function, or in a patch
of its own.

Both of the things I raised on v6 are right in this version. The power
domain list is attached before anything that would have to be unwound,
and the comment saying why a plain return is correct there is a good
addition. clks[] grows in the same patch that adds the two names.

I also went looking for an ARRAY_SIZE(core->clks) or
ARRAY_SIZE(core->resets) left behind, since that would walk six entries
on a four-clock RK3588. All six are converted in 7/10, including the
two in rocket_drv.c's runtime PM callbacks, which are the easiest pair
to miss.

Igor