Re: [PATCH v2] hw/core/resettable: make in-reset state false during exit phase call

[Peter Maydell]

On Fri, 22 Jan 2021 at 10:36, Damien Hedde <damien.hedde@greensocs.com> wrote:
>
> Move the reset count decrement from "just after" to "just before"
> calling the exit phase handler. The goal is to make
> resettable_is_in_reset() returning false during the handler execution.
>
> This simplifies reset handling in resettable devices.
>
> Typically, a function that updates the device state will just need
> to read the current reset state and not anymore treat the "in
> a reset-exit transition" special case.
>
> As a side note, this patch also fixes the fact that the reset count was
> not decremented in case of recursive reset.

This seems like a reasonable change and looking through the
sources it shouldn't break anything.

> diff --git a/docs/devel/reset.rst b/docs/devel/reset.rst
> index abea1102dc..021a7277a2 100644
> --- a/docs/devel/reset.rst
> +++ b/docs/devel/reset.rst
> @@ -210,9 +210,9 @@ Polling the reset state
>  Resettable interface provides the ``resettable_is_in_reset()`` function.
>  This function returns true if the object parameter is currently under reset.
>
> -An object is under reset from the beginning of the *init* phase to the end of
> -the *exit* phase. During all three phases, the function will return that the
> -object is in reset.
> +An object is under reset from the beginning of the *init* phase to the *exit*
> +phase. During *init* and *hold* phase only, the function will return that the
> +object is in reset. The state is changed just before calling the *exit* 
> method.

There is no "init" phase -- the documentation and the data structures
name the phases "enter", "hold" and "exit". Agreed with Philippe
about saying "beginning of the *enter* phase to the beginning of the
*exit* phase" (but an ascii art diagram is probably overkill).

thanks
-- PMM