tftp: adjust settings to be suitable for 100Mbit ethernet

Adjust timouts and retry counts to be suitable for loaded ethernet
network. With 5 seconds timeout, 10 retries maximum, tftp is
impossible even on local network with single full-speed TCP
connection.

100msec timeout should be suitable for most networks tftp is used on,
that is local ethernets. Timeout count really needs to be way higher,
as lost packets are normal when TCP is running over the same network.

Enforce 10msec minimum.

Signed-off-by: Pavel Machek <pavel@denx.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

net/tftp.c

@@ -19,10 +19,10 @@
 /* Well known TFTP port # */
 #define WELL_KNOWN_PORT	69
 /* Millisecs to timeout for lost pkt */
-#define TIMEOUT		5000UL
+#define TIMEOUT		100UL
 #ifndef	CONFIG_NET_RETRY_COUNT
 /* # of timeouts before giving up */
-# define TIMEOUT_COUNT	10
+# define TIMEOUT_COUNT	1000
 #else
 # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT * 2)
 #endif
@@ -711,10 +711,10 @@ void tftp_start(enum proto_t protocol)
 	if (ep != NULL)
 		timeout_ms = simple_strtol(ep, NULL, 10);
 
-	if (timeout_ms < 1000) {
-		printf("TFTP timeout (%ld ms) too low, set min = 1000 ms\n",
+	if (timeout_ms < 10) {
+		printf("TFTP timeout (%ld ms) too low, set min = 10 ms\n",
 		       timeout_ms);
-		timeout_ms = 1000;
+		timeout_ms = 10;
 	}
 
 	debug("TFTP blocksize = %i, timeout = %ld ms\n",