Messages in this thread | | | From | Stephen Boyd <> | Subject | Re: [PATCH] clk:mmp: clk-mix.c fix divide-by-zero | Date | Fri, 29 Mar 2019 15:48:14 -0700 |
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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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