Re: [PATCH 1/4] pwm: mxs: implement ->apply

[Uwe Kleine-König]

Hello,

[expanded the recipents to include RMK and the clk list]

On Mon, Sep 23, 2019 at 11:04:39AM +0200, Rasmus Villemoes wrote:
> On 23/09/2019 10.24, Uwe Kleine-König wrote:
> > Also there is a bug already in .config: You are not supposed to call
> > clk_get_rate if the clk might be off.
> 
> Interesting, I didn't know that. So the prepare_enable logic needs to be
> moved before we start computing the period/duty cycles. Do you know why
> it has apparently worked so far? I would have thought such a rule would
> be enforced by the clock framework, or at least produced a warning.

FTR: This is documented in the kerneldoc code comment to clk_get_rate in
include/linux/clk.h.

Assuming this is relevant, it might indeed make sense to add a
WARN_ONCE for this.

Best regards
Uwe

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