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Message-id: <566E9A4F.1030203@samsung.com>
Date: Mon, 14 Dec 2015 11:30:39 +0100
From: Andrzej Hajda <a.hajda@...sung.com>
To: Stephen Boyd <sboyd@...eaurora.org>
Cc: linux-kernel@...r.kernel.org,
Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
Marek Szyprowski <m.szyprowski@...sung.com>,
Michael Turquette <mturquette@...libre.com>,
linux-clk@...r.kernel.org
Subject: Re: [PATCH v2 14/38] clk: vt8500: fix sign of possible PLL values
Hi,
Ping.
Regards
Andrzej
On 10/02/2015 06:49 AM, Andrzej Hajda wrote:
> 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 <a.hajda@...sung.com>
> ---
> 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;
>
--
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