With unsigned values underflow in loops can occur resulting in theoretically infinite loops.
The problem has been detected using proposed semantic patch scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576 Signed-off-by: Andrzej Hajda <[email protected]> --- Hi Stephen, This is modified version according to your request, ie only problematic variables have changed type. I still think that 1st version is better, but of course it is up to you. Regards Andrzej drivers/clk/clk-vt8500.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c index 37e9288..98c4492 100644 --- a/drivers/clk/clk-vt8500.c +++ b/drivers/clk/clk-vt8500.c @@ -384,7 +384,8 @@ static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate, static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *multiplier, u32 *divisor1, u32 *divisor2) { - u32 mul, div1, div2; + u32 mul, div1; + int div2; u32 best_mul, best_div1, best_div2; unsigned long tclk, rate_err, best_err; @@ -452,7 +453,8 @@ static u32 wm8750_get_filter(u32 parent_rate, u32 divisor1) static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *filter, u32 *multiplier, u32 *divisor1, u32 *divisor2) { - u32 mul, div1, div2; + u32 mul; + int div1, div2; u32 best_mul, best_div1, best_div2; unsigned long tclk, rate_err, best_err; @@ -496,7 +498,8 @@ static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, static void wm8850_find_pll_bits(unsigned long rate, unsigned long parent_rate, u32 *multiplier, u32 *divisor1, u32 *divisor2) { - u32 mul, div1, div2; + u32 mul; + int div1, div2; u32 best_mul, best_div1, best_div2; unsigned long tclk, rate_err, best_err; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
