On Tue, Jun 13, 2023 at 11:25:12AM -0700, Stephen Boyd wrote: > Quoting Maxime Ripard (2023-06-13 05:14:25) > > On Mon, Jun 12, 2023 at 05:10:35PM -0700, Stephen Boyd wrote: > > > Quoting Sebastian Reichel (2023-05-26 10:10:56) > > > > diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c > > > > index edfa94641bbf..66759fe28fad 100644 > > > > --- a/drivers/clk/clk-composite.c > > > > +++ b/drivers/clk/clk-composite.c > > > > @@ -119,7 +119,10 @@ static int clk_composite_determine_rate(struct clk_hw *hw, > > > > if (ret) > > > > continue; > > > > > > > > - rate_diff = abs(req->rate - tmp_req.rate); > > > > + if (req->rate >= tmp_req.rate) > > > > + rate_diff = req->rate - tmp_req.rate; > > > > + else > > > > + rate_diff = tmp_req.rate - req->rate; > > > > > > This problem is widespread > > > > > > $ git grep abs\(.*- -- drivers/clk/ | wc -l > > > 52 > > > > > > so we may have a bigger problem here. Maybe some sort of coccinelle > > > script or smatch checker can be written to look for abs() usage with an > > > unsigned long type or a subtraction expression. This may also be worse > > > after converting drivers to clk_hw_forward_rate_request() and > > > clk_hw_init_rate_request() because those set the rate to ULONG_MAX. > > > +Maxime for that as an FYI. > > > > We set max_rate to ULONG_MAX in those functions, and I don't think we > > have a lot of driver that will call clk_round_rate on the max rate, so > > we should be somewhat ok? > > Good point. I haven't looked to see if any drivers are using the > max_rate directly. Hopefully they aren't. I had a quick grep for 'req->max_rate' under drivers/clk and there's no driver using abs on that field. Maxime
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