net: make net_random_ethaddr() more random

The net_random_ethaddr() tries to get some entropy from different
startup times of a board. The seed is initialized with get_timer() which
has only a granularity of milliseconds. We can do better if we use
get_ticks() which returns the raw timer ticks. Using this we have a
higher chance of getting different values at startup.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/include/net.h b/include/net.h
index a54d5eeac5fc95232089ac2f577ec0ffec667e23..75a16e4c8f8f51478f5ff7c2b53a0b764c27967e 100644 (file)
--- a/include/net.h
+++ b/include/net.h
@@ -816,7 +816,7 @@ static inline int is_valid_ethaddr(const u8 *addr)
 static inline void net_random_ethaddr(uchar *addr)
 {
        int i;
-       unsigned int seed = get_timer(0);
+       unsigned int seed = get_ticks();
 
        for (i = 0; i < 6; i++)
                addr[i] = rand_r(&seed);