[TIGON3]: Do not touch NIC_SRAM_FIRMWARE_MBOX when TG3_FLG2_SUN_570X.

There is no firmware on these chips, so accessing this
value is pointless.  But, more importantly, touching
this area on such chips results in PCI PIO timeouts.
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tg3.c

@@ -3697,6 +3697,7 @@ static void tg3_nvram_unlock(struct tg3 *tp)
 /* tp->lock is held. */
 static void tg3_write_sig_pre_reset(struct tg3 *tp, int kind)
 {
+	if (!(tp->tg3_flags2 & TG3_FLG2_SUN_570X))
 		tg3_write_mem(tp, NIC_SRAM_FIRMWARE_MBOX,
 			      NIC_SRAM_FIRMWARE_MBOX_MAGIC1);
 
@@ -3902,6 +3903,7 @@ static int tg3_chip_reset(struct tg3 *tp)
 		tw32_f(MAC_MODE, 0);
 	udelay(40);
 
+	if (!(tp->tg3_flags2 & TG3_FLG2_SUN_570X)) {
 		/* Wait for firmware initialization to complete. */
 		for (i = 0; i < 100000; i++) {
 			tg3_read_mem(tp, NIC_SRAM_FIRMWARE_MBOX, &val);
@@ -3909,13 +3911,13 @@ static int tg3_chip_reset(struct tg3 *tp)
 				break;
 			udelay(10);
 		}
-	if (i >= 100000 &&
-	    !(tp->tg3_flags2 & TG3_FLG2_SUN_570X)) {
+		if (i >= 100000) {
 			printk(KERN_ERR PFX "tg3_reset_hw timed out for %s, "
 			       "firmware will not restart magic=%08x\n",
 			       tp->dev->name, val);
 			return -ENODEV;
 		}
+	}
 
 	if ((tp->tg3_flags2 & TG3_FLG2_PCI_EXPRESS) &&
 	    tp->pci_chip_rev_id != CHIPREV_ID_5750_A0) {