net: make ARP timeout configurable

Currently the timeout waiting for an ARP reply is hard set to 5 seconds.
On i.MX31ADS due to a hardware "strangeness" up to four first IP packets
to the boards get lost, which typically are ARP replies. By configuring
the timeout to a lower value we significantly improve the first network
transfer time on this board. The timeout is specified in milliseconds,
later internally it is converted to deciseconds, because it has to be
converted to hardware ticks, and CFG_HZ ranges from 900 to 27000000 on
different boards.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>

diff --git a/README b/README
index 36ae0fb..5e2bca4 100644 (file)
--- a/README
+++ b/README
@@ -1561,6 +1561,10 @@ The following options need to be configured:
                before giving up the operation. If not defined, a
                default value of 5 is used.
 
+               CONFIG_ARP_TIMEOUT
+
+               Timeout waiting for an ARP reply in milliseconds.
+
 - Command Interpreter:
                CONFIG_AUTO_COMPLETE
 

diff --git a/net/net.c b/net/net.c
index 44feee2..b6dad89 100644 (file)
--- a/net/net.c
+++ b/net/net.c
@@ -94,11 +94,22 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#define ARP_TIMEOUT            5UL             /* Seconds before trying ARP again */
+#ifndef        CONFIG_ARP_TIMEOUT
+# define ARP_TIMEOUT           50UL    /* Deciseconds before trying ARP again */
+#elif (CONFIG_ARP_TIMEOUT < 100)
+# error "Due to possible overflow CONFIG_ARP_TIMEOUT must be greater than 100ms"
+#else
+# if (CONFIG_ARP_TIMEOUT % 100)
+#  warning "Supported ARP_TIMEOUT precision is 100ms"
+# endif
+# define ARP_TIMEOUT           (CONFIG_ARP_TIMEOUT / 100)
+#endif
+
+
 #ifndef        CONFIG_NET_RETRY_COUNT
-# define ARP_TIMEOUT_COUNT     5               /* # of timeouts before giving up  */
+# define ARP_TIMEOUT_COUNT     5       /* # of timeouts before giving up  */
 #else
-# define ARP_TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT)
+# define ARP_TIMEOUT_COUNT     CONFIG_NET_RETRY_COUNT
 #endif
 
 #if 0
@@ -129,7 +140,7 @@ uchar               NetOurEther[6];         /* Our ethernet address                 */
 uchar          NetServerEther[6] =     /* Boot server enet address             */
                        { 0, 0, 0, 0, 0, 0 };
 IPaddr_t       NetOurIP;               /* Our IP addr (0 = unknown)            */
-IPaddr_t       NetServerIP;            /* Our IP addr (0 = unknown)            */
+IPaddr_t       NetServerIP;            /* Server IP addr (0 = unknown)         */
 volatile uchar *NetRxPkt;              /* Current receive packet               */
 int            NetRxPktLen;            /* Current rx packet length             */
 unsigned       NetIPID;                /* IP packet ID                         */
@@ -253,7 +264,7 @@ void ArpTimeoutCheck(void)
        t = get_timer(0);
 
        /* check for arp timeout */
-       if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT * CFG_HZ) {
+       if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT * CFG_HZ / 10) {
                NetArpWaitTry++;
 
                if (NetArpWaitTry >= ARP_TIMEOUT_COUNT) {
@@ -494,7 +505,7 @@ restart:
                 *      Check the ethernet for a new packet.  The ethernet
                 *      receive routine will process it.
                 */
-                       eth_rx();
+               eth_rx();
 
                /*
                 *      Abort if ctrl-c was pressed.