Re: [PATCH RFC 0/2] clk: meson: g12a: handle clock hw changes while in suspend

From: Kevin Hilman
Date: Thu Sep 26 2019 - 16:46:33 EST


Neil Armstrong <narmstrong@xxxxxxxxxxxx> writes:

> This serie aime to support when the suspend/resume firmware alters the
> clock tree, leading to an incorrect representation of the clock tree
> after a resume from suspend-to-mem.
>
> For the Amlogic G12A/G12B/SM1 case, the SCPI firmware handling suspend
> alters the CPU clock tree in various ways.
>
> Since we know which part of the tree is possibly altered, we introduce here
> the clk_invalidate_rate() function that will rebuild the tree from the
> hardware registers in case parents and dividers have changed.
>
> Finally we call clk_invalidate_rate() from a new resume callback to refresh
> the CPU clock tree after a resume.
>
> With the clock tree refreshed, CCF can now handle the new clock tree
> configuration and avoid crashing the system on further DVFS set_rates.

For clarification, does this series work without the other proposed
fixes[1]? or is this dependent on that?

Kevin

[1] https://lore.kernel.org/linux-amlogic/20190919093627.21245-1-narmstrong@xxxxxxxxxxxx/