[U-Boot] [PATCH] Fix wrong loop bound in flush_cache() when "size" is zero.

[Sergei Shtylyov]

Hello.

On 08-08-2011 12:07, Yao Cheng wrote:

> The issue is found when calling flush_cache() with zero "size" argument.
> The bound of loop is miscalculated in this case and flush_cache() enters a wrong flushing loop.
> To fix this issue I skipped the operations when "size" is found to be zero.

> Signed-off-by: Yao Cheng<saturdaycoder at gmail.com>
> Cc: Shinya Kuribayashi<skuribay at pobox.com>
> ---
>   arch/mips/cpu/mips32/cpu.c |    5 +++++
>   1 files changed, 5 insertions(+), 0 deletions(-)

> diff --git a/arch/mips/cpu/mips32/cpu.c b/arch/mips/cpu/mips32/cpu.c
> index 3ae397c..1bf0094 100644
> --- a/arch/mips/cpu/mips32/cpu.c
> +++ b/arch/mips/cpu/mips32/cpu.c
> @@ -52,6 +52,11 @@ int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>
>   void flush_cache(ulong start_addr, ulong size)
>   {
> +  /* aend will be miscalculated when size is zero, so we need return here */
> +  if (size == 0) {
> +    return;
> +  }
 > +

    Please indent with tabs, not spaces. Also, doesn't this code generate 
warning (code before declarations)?

>   	unsigned long lsize = CONFIG_SYS_CACHELINE_SIZE;
>   	unsigned long addr = start_addr&  ~(lsize - 1);
>   	unsigned long aend = (start_addr + size - 1)&  ~(lsize - 1);

WBR, Sergei