Re: [PATCH v2 2/3] clk: ingenic: Mark critical clocks in Ingenic SoCs

From: Stephen Boyd
Date: Wed May 18 2022 - 16:58:03 EST


Quoting Aidan MacDonald (2022-04-28 09:44:53)
> Consider CPU, L2 cache, and memory clocks as critical to prevent
> them -- and the parent clocks -- from being automatically gated,
> since nothing calls clk_get() on these clocks.
>
> Gating the CPU clock hangs the processor, and gating memory makes
> external DRAM inaccessible. Normal kernel code can't hope to deal
> with either situation so those clocks have to be critical.
>
> The L2 cache is required only if caches are running, and could be
> gated if the kernel takes care to flush and disable caches before
> gating the clock. There's no mechanism to do this, and probably no
> reason to do it, so it's simpler to mark the L2 cache as critical.
>
> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@xxxxxxxxx>
> Reviewed-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> ---

Applied to clk-next