Re: [PATCH v12 08/11] pwm: sun4i: Use nsecs_to_jiffies to avoid a division

From: Guru Das Srinagesh
Date: Fri Apr 10 2020 - 15:21:00 EST


On Wed, Apr 08, 2020 at 11:52:37PM -0700, Guru Das Srinagesh wrote:
> Since the PWM framework is switching struct pwm_state.period's datatype
> to u64, prepare for this transition by using nsecs_to_jiffies() which
> does away with the need for a division operation.
>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Chen-Yu Tsai <wens@xxxxxxxx>
> Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
>
> Signed-off-by: Guru Das Srinagesh <gurus@xxxxxxxxxxxxxx>
> ---
> drivers/pwm/pwm-sun4i.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> index 5c677c5..1694e69 100644
> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -285,7 +285,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
> sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
> sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
> - usecs_to_jiffies(cstate.period / 1000 + 1);
> + nsecs_to_jiffies(cstate.period + 1000);
>
> if (state->polarity != PWM_POLARITY_NORMAL)
> ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm);
> --

Hi Chen-Yu,

You had provided your "Acked-by:" [1] for an earlier version of this
patch but now that I've revised the patch based on a review comment I
received [2], could you please review this patch once again?

Thank you.

Guru Das.

[1] https://www.spinics.net/lists/linux-pwm/msg11755.html
[2] https://www.spinics.net/lists/linux-pwm/msg11956.html