Re: [U-Boot] [PATCH v2] tools: gen_eth_addr: add getpid() to time(0) to avoid duplicated seed

Dear Josh Wu,

In message 1442398864-1312-1-git-send-email-josh.wu@atmel.com you wrote:

As 'time(0) | getpid()' will have a lot of duplicated value. It is not a expected behavior. We expect different value for the seed when when run it in many times.

So this patch will left shift the getpid() and add to time(0). That avoid duplicated value.

Test command is like: % RUN=0; while [ $RUN -lt 10000 ]; do tools/gen_eth_addr; RUN=$(($RUN+1)); done | sort | uniq | wc -l 10000

This patch is incorporated with suggestions made by Wolfgang Denk and Andreas Bießmann. Thanks them a lot.

Signed-off-by: Josh Wu josh.wu@atmel.com

Changes in v2:

• left shift and add the getpid() value instead of removing it.

tools/gen_eth_addr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

I ran this version through a total of 80,000 runs ; there were no duplicated addresses found in this test.

Acked-by: Wolfgang Denk wd@denx.de Tested-by: Wolfgang Denk wd@denx.de

Thanks!

Best regards,

Wolfgang Denk