[U-Boot] [PATCH 22/28] net: Fix net buffer initialization

[Joe Hershberger]

A new non-static function NetInit() will initialize buffers and read
   from the env
Only update from the env on each entry to NetLoop()
Check when attempting to send a packet that the buffers were initialized

Signed-off-by: Joe Hershberger <joe.hershberger at ni.com>
Cc: Joe Hershberger <joe.hershberger at gmail.com>
Cc: Wolfgang Denk <wd at denx.de>
---
 include/net.h |    7 ++++---
 net/net.c     |   48 +++++++++++++++++++++++++++++++++---------------
 2 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/include/net.h b/include/net.h
index af6a803..1861406 100644
--- a/include/net.h
+++ b/include/net.h
@@ -400,7 +400,8 @@ extern IPaddr_t Mcast_addr;
 #endif
 
 /* Initialize the network adapter */
-extern int NetLoop(enum proto_t);
+extern void	NetInit(void);
+extern int	NetLoop(enum proto_t protocol);
 
 /* Shutdown adapters and cleanup */
 extern void	NetStop(void);
@@ -439,10 +440,10 @@ extern void	NetSetState(int state);
 #define NETLOOP_SUCCESS		3
 #define NETLOOP_FAIL		4
 
-/* Transmit "NetTxPacket" */
+/* Transmit a packet */
 extern void NetSendPacket(uchar *, int);
 
-/* Transmit UDP packet, performing ARP request if needed
+/* Transmit "NetTxPacket" as UDP packet, performing ARP request if needed
    (ether will be populated) */
 extern int	NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport,
 			int sport, int payload_len);
diff --git a/net/net.c b/net/net.c
index 1c0c822..51d899b 100644
--- a/net/net.c
+++ b/net/net.c
@@ -236,7 +236,7 @@ void net_auto_load(void)
 	TftpStart(TFTPGET);
 }
 
-static void NetInitLoop(enum proto_t protocol)
+static void NetInitLoop(void)
 {
 	static int env_changed_id;
 	bd_t *bd = gd->bd;
@@ -269,6 +269,30 @@ NetCleanupLoop(void)
 	NetSetTimeout(0, NULL);
 }
 
+void
+NetInit(void)
+{
+	static int first_call = 1;
+
+	if (first_call) {
+		/*
+		 *	Setup packet buffers, aligned correctly.
+		 */
+		int i;
+		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
+		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
+		for (i = 0; i < PKTBUFSRX; i++)
+			NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
+
+		ArpInit();
+
+		/* Only need to setup buffer pointers once. */
+		first_call = 0;
+	}
+
+	NetInitLoop();
+}
+
 /**********************************************************************/
 /*
  *	Main network processing loop.
@@ -276,26 +300,14 @@ NetCleanupLoop(void)
 
 int NetLoop(enum proto_t protocol)
 {
-	int	i;
 	bd_t *bd = gd->bd;
 	int ret = -1;
 
 	NetRestarted = 0;
 	NetDevExists = 0;
-
-	NetTxPacket = NULL;
 	NetTryCount = 1;
 
-	ArpInit();
-
-	/*
-	 *	Setup packet buffers, aligned correctly.
-	 */
-	NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
-	NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
-	for (i = 0; i < PKTBUFSRX; i++)
-		NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
-
+	NetInit();
 	eth_halt();
 	eth_set_current();
 	if (eth_init(bd) < 0) {
@@ -313,7 +325,7 @@ restart:
 	 *	here on, this code is a state machine driven by received
 	 *	packets and timer events.
 	 */
-	NetInitLoop(protocol);
+	NetInitLoop();
 
 	switch (net_check_prereq(protocol)) {
 	case 1:
@@ -627,6 +639,12 @@ NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
 {
 	uchar *pkt;
 
+	/* make sure the NetTxPacket is initialized (NetInit() was called) */
+	if (NetTxPacket == NULL) {
+		puts("*** ERROR: NetTxPacket buffer pointer is NULL!\n");
+		return -1;
+	}
+
 	/* convert to new style broadcast */
 	if (dest == 0)
 		dest = 0xFFFFFFFF;
-- 
1.6.0.2