Re: [PATCH v1] clk: Add devm_clk_{prepare,enable,prepare_enable}

From: Marc Gonzalez
Date: Mon Nov 25 2019 - 08:10:25 EST


On 25/11/2019 13:55, Russell King - ARM Linux admin wrote:

> It's also worth reading https://lore.kernel.org/patchwork/patch/755667/
> and considering whether you really are using the clk_prepare() and
> clk_enable() APIs correctly. Wanting these devm functions suggests
> you aren't...

In that older thread, you wrote:

> If you take the view that trying to keep clocks disabled is a good way
> to save power, then you'd have the clk_prepare() or maybe
> clk_prepare_enable() in your run-time PM resume handler, or maybe even
> deeper in the driver... the original design goal of the clk API was to
> allow power saving and clock control.
>
> With that in mind, getting and enabling the clock together in the
> probe function didn't make sense.
>
> I feel that aspect has been somewhat lost, and people now regard much
> of the clk API as a bit of a probe-time nuisance.

In the few drivers I've written, I call clk_prepare_enable() at probe.

And since clk_prepare_enable() is the only non-devm function in probe,
I need either a remove function, or an explicit registration step.

You seem to be saying I'm using the clk API in the wrong way?

Regards.