[PATCH 2/3] pwm: bcm2835: prevent division by zero

[Mathieu Poirier]

On 1 December 2015 at 15:55, Stefan Wahren <stefan.wahren at i2se.com> wrote:
> It's possible that the pwm clock become an orphan. So better
> check the result of clk_get_rate in order to prevent a division
> by zero.
>
> Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
> ---
>  drivers/pwm/pwm-bcm2835.c |   10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
> index 174cca9..31a6992 100644
> --- a/drivers/pwm/pwm-bcm2835.c
> +++ b/drivers/pwm/pwm-bcm2835.c
> @@ -65,7 +65,15 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>                               int duty_ns, int period_ns)
>  {
>         struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
> -       unsigned long scaler = NSEC_PER_SEC / clk_get_rate(pc->clk);
> +       unsigned long rate = clk_get_rate(pc->clk);
> +       unsigned long scaler;
> +
> +       if (!rate) {
> +               dev_err(pc->dev, "failed to get clock rate\n");
> +               return -EINVAL;
> +       }
> +
> +       scaler = NSEC_PER_SEC / rate;

Stefan,

Please merge this code into patch 1/3.  That way it is done the right
way the first time around.

Thanks,
Mathieu

>
>         if (period_ns <= MIN_PERIOD) {
>                 dev_err(pc->dev, "period %d not supported, minimum %d\n",
> --
> 1.7.9.5
>
>
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