Re: [PATCH] clk:mmp: clk-mix.c fix divide-by-zero

[Mukesh Ojha]

On 3/29/2019 5:16 PM, nixiaoming wrote:

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 <nixiaom...@huawei.com>

Fix the below minor comments..
Otherwise things look good..you can take mine
Reviewed-by: Mukesh Ojha <mo...@codeaurora.org>

after fixing it.


Cheers,
-Mukesh

---
  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 */

Please move this comment at the top of the check.

+                                       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 */

ditto

+               return -EINVAL;

return parent_rate / div;

  }