Quoting nixiaoming (2019-03-30 06:54:50) > In the function divider_recalc_rate() The judgment of the return value of > _get_div() indicates that the return value of _get_div() can be 0.
When does _get_div() return 0? It can't be CLK_DIVIDER_MAX_AT_ZERO or CLK_DIVIDER_POWER_OF_TWO. I suppose it could be CLK_DIVIDER_ONE_BASED if CLK_DIVIDER_ALLOW_ZERO is set? Or just CLK_DIVIDER_ALLOW_ZERO is set? Or a table that has 0 in it for some odd reason. > In order to avoid the divide-by-zero error, add check for return value > of _get_div() in the divider_ro_round_rate_parent() > > Signed-off-by: nixiaoming <nixiaom...@huawei.com> > Reviewed-by: Mukesh Ojha <mo...@codeaurora.org> > --- > drivers/clk/clk-divider.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c > index e5a1726..f4bf7a4 100644 > --- a/drivers/clk/clk-divider.c > +++ b/drivers/clk/clk-divider.c > @@ -347,6 +347,9 @@ long divider_ro_round_rate_parent(struct clk_hw *hw, > struct clk_hw *parent, > int div; > > div = _get_div(table, val, flags, width); > + /* avoid divide-by-zero */ > + if (!div) > + return -EINVAL; Can you please give more details on what's happening here? Who's the caller? What are the arguments being passed in? Shouldn't we check for CLK_DIVIDER_ALLOW_ZERO and then return prate as it comes in instead of returning an error? > > /* Even a read-only clock can propagate a rate change */ > if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {