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SubjectRe: [PATCH] clk:mmp: clk-mix.c fix divide-by-zero
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Quoting nixiaoming (2019-03-29 04:46:00)
> The _get_div function has a branch with a return value of 0
> Add a check on the return value of _get_div to avoid divide-by-zero
>
> Signed-off-by: nixiaoming <nixiaoming@huawei.com>

Similar questions apply here as they do on the generic divider patch you
sent.

> ---
> drivers/clk/mmp/clk-mix.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/clk/mmp/clk-mix.c b/drivers/clk/mmp/clk-mix.c
> index 90814b2..9d152c2 100644
> --- a/drivers/clk/mmp/clk-mix.c
> +++ b/drivers/clk/mmp/clk-mix.c
> @@ -245,6 +245,8 @@ static int mmp_clk_mix_determine_rate(struct clk_hw *hw,
> div_val_max = _get_maxdiv(mix);
> for (j = 0; j < div_val_max; j++) {
> div = _get_div(mix, j);
> + if (!div) /* avoid divide-by-zero */

Why can't we return 1 for the divider value here?

> + continue;
> mix_rate = parent_rate / div;
> gap = abs(mix_rate - req->rate);
> if (!parent_best || gap < gap_best) {
> @@ -341,6 +343,8 @@ static unsigned long mmp_clk_mix_recalc_rate(struct clk_hw *hw,
> shift = mix->reg_info.shift_div;
>
> div = _get_div(mix, MMP_CLK_BITS_GET_VAL(mux_div, width, shift));
> + if (!div) /* avoid divide-by-zero */

Same question.

> + return -EINVAL;
>
> return parent_rate / div;
> }

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