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

Jean-Christophe PLAGNIOL-VILLARD
2009-04-13T22:09:26Z

On 14:28 Fri 10 Apr , Renato Andreola wrote:
> From 6cc63851e5e4c16012d9afad70cedb41b7340de7 Mon Sep 17 00:00:00 2001
> From: Renato Andreola <renato.andreola@imagos.it>
> Date: Fri, 10 Apr 2009 12:52:55 +0200
> Subject: 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
> ---
> drivers/mtd/cfi_flash.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
> index 175d82a..0aa42a2 100644
> --- a/drivers/mtd/cfi_flash.c
> +++ b/drivers/mtd/cfi_flash.c
> @@ -660,7 +660,9 @@ 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;
> + unsigned long long ull;
> + ull = tout*CONFIG_SYS_HZ + CONFIG_SYS_HZ/2;
> + tout = ull/1000; /* Compute: tout *= CONFIG_SYS_HZ/1000; */
> #endif
drop all of this and fix your CONFIG_SYS_HZ to 1000 (non configurable value)
will be better

Best Regards,
J.