From bab53301c3846ae9a5e1142dca2976f434f70481 Mon Sep 17 00:00:00 2001 From: Haojian Zhuang Date: Mon, 3 Dec 2012 16:14:37 +0800 Subject: [PATCH] clk: fixed-factor: round_rate should use do_div clk->rate = parent->rate / div * mult The formula is OK. But it may overflow while we do operate with unsigned long. So use do_div instead. Signed-off-by: Haojian Zhuang Signed-off-by: Mike Turquette [mturquette@linaro.org: improved $SUBJECT] --- drivers/clk/clk-fixed-factor.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index a4899855c0f6..1ef271e47594 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -28,8 +28,11 @@ static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); + unsigned long long int rate; - return parent_rate * fix->mult / fix->div; + rate = (unsigned long long int)parent_rate * fix->mult; + do_div(rate, fix->div); + return (unsigned long)rate; } static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate, -- 2.20.1