[3c90x] Stall upload engine before setting RX ring address

According to the 3c90x datasheet we have to stall the upload (receive)
engine before setting the receive ring address.

Signed-off-by: Thomas Miletich <thomas.miletich@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/3c90x.c

@@ -813,10 +813,14 @@ static int a3c90x_open(struct net_device *netdev)
 		goto error;
 	}
 
+	a3c90x_internal_IssueCommand(inf_3c90x->IOAddr, cmdStallCtl, upStall);
+
 	/* send rx_ring address to NIC */
 	outl(virt_to_bus(inf_3c90x->rx_ring),
 	     inf_3c90x->IOAddr + regUpListPtr_l);
 
+	a3c90x_internal_IssueCommand(inf_3c90x->IOAddr, cmdStallCtl, upUnStall);
+
 	/* enable packet transmission and reception */
 	a3c90x_internal_IssueCommand(inf_3c90x->IOAddr, cmdTxEnable, 0);
 	a3c90x_internal_IssueCommand(inf_3c90x->IOAddr, cmdRxEnable, 0);