Re: [PATCH 1/2] pwm: meson: consider 128 a valid pre-divider

From: Neil Armstrong
Date: Wed Apr 03 2019 - 07:19:46 EST


On 01/04/2019 20:18, Martin Blumenstingl wrote:
> The pre-divider allows configuring longer PWM periods compared to using
> the input clock directly. The pre-divider is 7 bit wide, meaning it's
> maximum value is 128 (the register value is off-by-one: 0x7f or 127).
>
> Change the loop to also allow for the maximum possible value to be
> considered valid.
>
> Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
> drivers/pwm/pwm-meson.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> index f6e738ad7bd9..4b708c1fcb1d 100644
> --- a/drivers/pwm/pwm-meson.c
> +++ b/drivers/pwm/pwm-meson.c
> @@ -188,7 +188,7 @@ static int meson_pwm_calc(struct meson_pwm *meson,
> do_div(fin_ps, fin_freq);
>
> /* Calc pre_div with the period */
> - for (pre_div = 0; pre_div < MISC_CLK_DIV_MASK; pre_div++) {
> + for (pre_div = 0; pre_div <= MISC_CLK_DIV_MASK; pre_div++) {
> cnt = DIV_ROUND_CLOSEST_ULL((u64)period * 1000,
> fin_ps * (pre_div + 1));
> dev_dbg(meson->chip.dev, "fin_ps=%llu pre_div=%u cnt=%u\n",
> @@ -197,7 +197,7 @@ static int meson_pwm_calc(struct meson_pwm *meson,
> break;
> }
>
> - if (pre_div == MISC_CLK_DIV_MASK) {
> + if (pre_div > MISC_CLK_DIV_MASK) {
> dev_err(meson->chip.dev, "unable to get period pre_div\n");
> return -EINVAL;
> }
>

Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>