Re: [PATCH v5 34/46] clk: pwm: switch to the atomic API

Stephen Boyd
2016-03-30T22:01:49Z

On 03/30, Boris Brezillon wrote:
> diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
> index ebcd738..49ec5b1 100644
> --- a/drivers/clk/clk-pwm.c
> +++ b/drivers/clk/clk-pwm.c
> @@ -28,15 +28,29 @@ static inline struct clk_pwm *to_clk_pwm(struct clk_hw *hw)
> static int clk_pwm_prepare(struct clk_hw *hw)
> {
> struct clk_pwm *clk_pwm = to_clk_pwm(hw);
> + struct pwm_state pstate;
>
> - return pwm_enable(clk_pwm->pwm);
> + pwm_get_state(clk_pwm->pwm, &pstate);
> + if (pstate.enabled)
> + return 0;
> +
> + pstate.enabled = true;
> +
> + return pwm_apply_state(clk_pwm->pwm, &pstate);

This doesn't seem atomic anymore if we're checking the state and
then not calling apply_state if it's already enabled. But I
assume this doesn't matter because we "own" the pwm here?
Otherwise I would think this would be unconditional apply state
and duplicates would be ignored in the pwm framework.

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