Dear Renato Andreola,
In message <4a7aa72c.8010...@imagos.it> you wrote:
> From be54cb97ca26bcbbc1a908d1f2a5447b6639dc59 Mon Sep 17 00:00:00 2001
> From: Renato Andreola <renato.andre...@imagos.it>
> Date: Thu, 6 Aug 2009 11:40:52 +0200
> Subject: [PATCH] drivers/mtd/cfi_flash: precision and underflow problem
> in tout calculation
>
> With old configuration it could happen tout=0 if CONFIG_SYS_HZ<1000
> solved using an unsigned long long
I don't like this implementation - using LL divisions just pulls in
more dependencies on libgcc code and the like, and blows up the code
size.
> -#if CONFIG_SYS_HZ != 1000
> - tout *= CONFIG_SYS_HZ/1000;
> +#if CONFIG_SYS_HZ != 1000
> + unsigned long long ull;
> + ull = tout*CONFIG_SYS_HZ + CONFIG_SYS_HZ/2;
> + tout = ull/1000; /* Compute: tout *= CONFIG_SYS_HZ/1000; */
I think rounding up should be sufficient here, i. e. something like:
tout *= DIV_ROUND_UP(CONFIG_SYS_HZ,1000);
?
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
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