[U-Boot] PATCH mtd CFI flash: timeout calculation underflow if imprecise 1kHz timer: fix

[Jean-Christophe PLAGNIOL-VILLARD]

On 15:09 Thu 06 Aug     , Renato Andreola wrote:
>  From 3723c8437d8c3d2e04bc3bc1de9c21b33072ab08 Mon Sep 17 00:00:00 2001
> From: Renato Andreola <renato.andreola at imagos.it>
> Date: Thu, 6 Aug 2009 14:49:59 +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 avoiding the preprocessor conditional and introducing a compile 
> time branch between a high freq case and a slow freq case.
> 
> Signed-off-by: Renato Andreola renato.andreola at imagos.it
> ---
>   drivers/mtd/cfi_flash.c |    7 ++++---
>   1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
> index 81ac5d3..b118f71 100644
> --- a/drivers/mtd/cfi_flash.c
> +++ b/drivers/mtd/cfi_flash.c
> @@ -659,9 +659,10 @@ static int flash_status_check (flash_info_t * info, 
> flash_sect_t sector,
>   {
>   	ulong start;
> 
> -#if CONFIG_SYS_HZ != 1000
> -	tout *= CONFIG_SYS_HZ/1000;
> -#endif
> +        if (CONFIG_SYS_HZ > 10000)
> +                tout *= CONFIG_SYS_HZ/1000;  /* for a big HZ, avoid 
> overflow */
> +        else
> +                tout = tout * CONFIG_SYS_HZ / 1000 + 1;
as we are all supposed to have CONFIG_SYS_HZ at 1000 (mandtory)
to have cfi, tftp & co working perfectly I do not thing this is a good idea

as you will need to fix each part of u-boot that use CONFIG_SYS_HZ
which make no sense

the best will be to simply fix your timer

Best Regards,
J.