net: mvneta: improve suspend/resume

Current suspend/resume implementation reuses the mvneta_open() and
mvneta_close(), but it could be optimized to take only necessary
actions during suspend/resume.

One obvious problem of current implementation is: after hundreds of
system suspend/resume cycles, the resume of mvneta could fail due to
fragmented dma coherent memory. After this patch, the non-necessary
memory alloc/free is optimized out.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvneta.c

@@ -4571,16 +4571,45 @@ static int mvneta_remove(struct platform_device *pdev)
 #ifdef CONFIG_PM_SLEEP
 static int mvneta_suspend(struct device *device)
 {
+	int queue;
 	struct net_device *dev = dev_get_drvdata(device);
 	struct mvneta_port *pp = netdev_priv(dev);
 
+	if (!netif_running(dev))
+		goto clean_exit;
+
+	if (!pp->neta_armada3700) {
+		spin_lock(&pp->lock);
+		pp->is_stopped = true;
+		spin_unlock(&pp->lock);
+
+		cpuhp_state_remove_instance_nocalls(online_hpstate,
+						    &pp->node_online);
+		cpuhp_state_remove_instance_nocalls(CPUHP_NET_MVNETA_DEAD,
+						    &pp->node_dead);
+	}
+
 	rtnl_lock();
-	if (netif_running(dev))
-		mvneta_stop(dev);
+	mvneta_stop_dev(pp);
 	rtnl_unlock();
+
+	for (queue = 0; queue < rxq_number; queue++) {
+		struct mvneta_rx_queue *rxq = &pp->rxqs[queue];
+
+		mvneta_rxq_drop_pkts(pp, rxq);
+	}
+
+	for (queue = 0; queue < txq_number; queue++) {
+		struct mvneta_tx_queue *txq = &pp->txqs[queue];
+
+		mvneta_txq_hw_deinit(pp, txq);
+	}
+
+clean_exit:
 	netif_device_detach(dev);
 	clk_disable_unprepare(pp->clk_bus);
 	clk_disable_unprepare(pp->clk);
+
 	return 0;
 }
 
@@ -4589,7 +4618,7 @@ static int mvneta_resume(struct device *device)
 	struct platform_device *pdev = to_platform_device(device);
 	struct net_device *dev = dev_get_drvdata(device);
 	struct mvneta_port *pp = netdev_priv(dev);
-	int err;
+	int err, queue;
 
 	clk_prepare_enable(pp->clk);
 	if (!IS_ERR(pp->clk_bus))
@@ -4611,12 +4640,38 @@ static int mvneta_resume(struct device *device)
 	}
 
 	netif_device_attach(dev);
-	rtnl_lock();
-	if (netif_running(dev)) {
-		mvneta_open(dev);
-		mvneta_set_rx_mode(dev);
+
+	if (!netif_running(dev))
+		return 0;
+
+	for (queue = 0; queue < rxq_number; queue++) {
+		struct mvneta_rx_queue *rxq = &pp->rxqs[queue];
+
+		rxq->next_desc_to_proc = 0;
+		mvneta_rxq_hw_init(pp, rxq);
+	}
+
+	for (queue = 0; queue < txq_number; queue++) {
+		struct mvneta_tx_queue *txq = &pp->txqs[queue];
+
+		txq->next_desc_to_proc = 0;
+		mvneta_txq_hw_init(pp, txq);
 	}
+
+	if (!pp->neta_armada3700) {
+		spin_lock(&pp->lock);
+		pp->is_stopped = false;
+		spin_unlock(&pp->lock);
+		cpuhp_state_add_instance_nocalls(online_hpstate,
+						 &pp->node_online);
+		cpuhp_state_add_instance_nocalls(CPUHP_NET_MVNETA_DEAD,
+						 &pp->node_dead);
+	}
+
+	rtnl_lock();
+	mvneta_start_dev(pp);
 	rtnl_unlock();
+	mvneta_set_rx_mode(dev);
 
 	return 0;
 }