net: mvneta: do not redirect frames during reconfiguration

Disable frames injection in mvneta_xdp_xmit routine during hw
re-configuration in order to avoid hardware hangs

Fixes: b0a43db9 ("net: mvneta: add XDP_TX support")
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvneta.c

@@ -452,11 +452,17 @@ struct mvneta_pcpu_port {
 	u32			cause_rx_tx;
 };
 
+enum {
+	__MVNETA_DOWN,
+};
+
 struct mvneta_port {
 	u8 id;
 	struct mvneta_pcpu_port __percpu	*ports;
 	struct mvneta_pcpu_stats __percpu	*stats;
 
+	unsigned long state;
+
 	int pkt_size;
 	void __iomem *base;
 	struct mvneta_rx_queue *rxqs;
@@ -2113,6 +2119,9 @@ mvneta_xdp_xmit(struct net_device *dev, int num_frame,
 	struct netdev_queue *nq;
 	u32 ret;
 
+	if (unlikely(test_bit(__MVNETA_DOWN, &pp->state)))
+		return -ENETDOWN;
+
 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 		return -EINVAL;
 
@@ -3568,12 +3577,16 @@ static void mvneta_start_dev(struct mvneta_port *pp)
 
 	phylink_start(pp->phylink);
 	netif_tx_start_all_queues(pp->dev);
+
+	clear_bit(__MVNETA_DOWN, &pp->state);
 }
 
 static void mvneta_stop_dev(struct mvneta_port *pp)
 {
 	unsigned int cpu;
 
+	set_bit(__MVNETA_DOWN, &pp->state);
+
 	phylink_stop(pp->phylink);
 
 	if (!pp->neta_armada3700) {