net: add 'ethrotate' environment variable

[PATCH] net: add 'ethrotate' environment variable

This patch replaces the buildtime configuration option
CONFIG_NET_DO_NOT_TRY_ANOTHER through the 'ethrotate' runtime
configuration veriable. See README.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>

README

@@ -2691,6 +2691,10 @@ Some configuration options can be set using Environment Variables:
 		  => setenv ethact SCC ETHERNET
 		  => ping 10.0.0.1 # traffic sent on SCC ETHERNET
 
+  ethrotate	- When set to "no" U-Boot does not go through all
+		  available network interfaces.
+		  It just stays at the currently selected interface.
+
    netretry	- When set to "no" each network operation will
 		  either succeed or fail without retrying.
 		  When set to "once" the network operation will

net/eth.c

@@ -525,6 +525,15 @@ int eth_receive(volatile void *packet, int length)
 void eth_try_another(int first_restart)
 {
 	static struct eth_device *first_failed = NULL;
+	char *ethrotate;
+
+	/*
+	 * Do not rotate between network interfaces when
+	 * 'ethrotate' variable is set to 'no'.
+	 */
+	if (((ethrotate = getenv ("ethrotate")) != NULL) &&
+	    (strcmp(ethrotate, "no") == 0))
+		return;
 
 	if (!eth_current)
 		return;