bnxt_en: Fix occasional ethtool -t loopback test failures

In the current code, we setup the port to PHY or MAC loopback mode
and then transmit a test broadcast packet for the loopback test.  This
scheme fails sometime if the port is shared with management firmware
that can also send packets.  The driver may receive the management
firmware's packet and the test will fail when the contents don't
match the test packet.

Change the test packet to use it's own MAC address as the destination
and setup the port to only receive it's own MAC address.  This should
filter out other packets sent by management firmware.

Fixes: 91725d89 ("bnxt_en: Add PHY loopback to ethtool self-test.")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -8639,6 +8639,9 @@ static int bnxt_init_chip(struct bnxt *bp, bool irq_re_init)
 	vnic->uc_filter_count = 1;
 
 	vnic->rx_mask = 0;
+	if (test_bit(BNXT_STATE_HALF_OPEN, &bp->state))
+		goto skip_rx_mask;
+
 	if (bp->dev->flags & IFF_BROADCAST)
 		vnic->rx_mask |= CFA_L2_SET_RX_MASK_REQ_MASK_BCAST;
 
@@ -8659,6 +8662,7 @@ static int bnxt_init_chip(struct bnxt *bp, bool irq_re_init)
 	if (rc)
 		goto err_out;
 
+skip_rx_mask:
 	rc = bnxt_hwrm_set_coal(bp);
 	if (rc)
 		netdev_warn(bp->dev, "HWRM set coalescing failure rc: %x\n",
@@ -10335,8 +10339,10 @@ int bnxt_half_open_nic(struct bnxt *bp)
 		netdev_err(bp->dev, "bnxt_alloc_mem err: %x\n", rc);
 		goto half_open_err;
 	}
+	set_bit(BNXT_STATE_HALF_OPEN, &bp->state);
 	rc = bnxt_init_nic(bp, true);
 	if (rc) {
+		clear_bit(BNXT_STATE_HALF_OPEN, &bp->state);
 		netdev_err(bp->dev, "bnxt_init_nic err: %x\n", rc);
 		goto half_open_err;
 	}
@@ -10357,6 +10363,7 @@ void bnxt_half_close_nic(struct bnxt *bp)
 	bnxt_hwrm_resource_free(bp, false, true);
 	bnxt_free_skbs(bp);
 	bnxt_free_mem(bp, true);
+	clear_bit(BNXT_STATE_HALF_OPEN, &bp->state);
 }
 
 void bnxt_reenable_sriov(struct bnxt *bp)

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1921,6 +1921,7 @@ struct bnxt {
 #define BNXT_STATE_RECOVER		12
 #define BNXT_STATE_FW_NON_FATAL_COND	13
 #define BNXT_STATE_FW_ACTIVATE_RESET	14
+#define BNXT_STATE_HALF_OPEN		15	/* For offline ethtool tests */
 
 #define BNXT_NO_FW_ACCESS(bp)					\
 	(test_bit(BNXT_STATE_FW_FATAL_COND, &(bp)->state) ||	\

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -3458,7 +3458,7 @@ static int bnxt_run_loopback(struct bnxt *bp)
 	if (!skb)
 		return -ENOMEM;
 	data = skb_put(skb, pkt_size);
-	eth_broadcast_addr(data);
+	ether_addr_copy(&data[i], bp->dev->dev_addr);
 	i += ETH_ALEN;
 	ether_addr_copy(&data[i], bp->dev->dev_addr);
 	i += ETH_ALEN;