Re: [RFC PATCH v6 7/9] accel/rocket: add RK3576 NPU (RKNN) support

[Jiaxing Hu]

Hi Chaoyi,

Thank you, that settles it, and no apology needed for not reading the
series.

> For RK3576:
>
> - BIT[15:0] task_number
> - BIT[16] task_pp_en
> - BIT[17] task_count_clear
> - BIT[18] task_last_layer_clear

That matches the register trace bit for bit, and it is worth more than
the trace, because the trace could only say which word the vendor writes
and not what the bits in it are.

BIT[18] is new to me. I was setting it because the vendor's word had it
set and clearing it was not something I wanted to try blind. Now it can
be named rather than shipped as 0x7 << 16:

  #define PC_TASK_CON_TASK_NUMBER		GENMASK(15, 0)
  #define PC_TASK_CON_TASK_PP_EN		BIT(16)
  #define PC_TASK_CON_TASK_COUNT_CLEAR		BIT(17)
  #define PC_TASK_CON_TASK_LAST_LAYER_CLEAR	BIT(18)

with the RK3588 positions kept beside them, since the two differ only in
the width of the first field and that is exactly what made v1 through v6
wrong.

One question, if you have a moment. Is task_last_layer_clear meant to be
set on every submit, or only on the task that ends a layer? Setting it
unconditionally works on RK3576 here, but working and being right are
not the same thing, and I would rather not encode a guess in a driver
other people will copy from.

Thanks again,
Jiaxing