RDMA/nes: Generate IB_EVENT_PORT_ERR/PORT_ACTIVE events

Depending on link state change, IB_EVENT_PORT_ERR or
IB_EVENT_PORT_ACTIVE should be generated when handling MAC interrupts.

Plugging in a cable happens to result in series of interrupts changing
driver's link state a number of times before finally staying at link
up (e.g. link up, link down, link up, link down, ..., link up). To
prevent sending series of redundant IB_EVENT_PORT_ACTIVE and
IB_EVENT_PORT_ERR events, we use a timer to debounce them in
nes_port_ibevent().

Signed-off-by: Maciej Sosnowski <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/hw/nes/nes_hw.c

···
 						netif_start_queue(nesvnic->netdev);
 					nesvnic->linkup = 1;
 					netif_carrier_on(nesvnic->netdev);
+
+					spin_lock(&nesvnic->port_ibevent_lock);
+					if (nesdev->iw_status == 0) {
+						nesdev->iw_status = 1;
+						nes_port_ibevent(nesvnic);
+					}
+					spin_unlock(&nesvnic->port_ibevent_lock);
 				}
 			}
 		} else {
···
 						netif_stop_queue(nesvnic->netdev);
 					nesvnic->linkup = 0;
 					netif_carrier_off(nesvnic->netdev);
+
+					spin_lock(&nesvnic->port_ibevent_lock);
+					if (nesdev->iw_status == 1) {
+						nesdev->iw_status = 0;
+						nes_port_ibevent(nesvnic);
+					}
+					spin_unlock(&nesvnic->port_ibevent_lock);
 				}
 			}
 		}

drivers/infiniband/hw/nes/nes_hw.h

···
 
 struct nes_ib_device;
 
+#define NES_EVENT_DELAY msecs_to_jiffies(100)
+
 struct nes_vnic {
 	struct nes_ib_device *nesibdev;
 	u64 sq_full;
···
 	u32 lro_max_aggr;
 	struct net_lro_mgr lro_mgr;
 	struct net_lro_desc lro_desc[NES_MAX_LRO_DESCRIPTORS];
+	struct timer_list event_timer;
+	enum ib_event_type delayed_event;
+	enum ib_event_type last_dispatched_event;
+	spinlock_t port_ibevent_lock;
 };
 
 struct nes_ib_device {

drivers/infiniband/hw/nes/nes_nic.c

···
 	u32 nic_active_bit;
 	u32 nic_active;
 	struct list_head *list_pos, *list_temp;
+	unsigned long flags;
 
 	assert(nesdev != NULL);
 
···
 		first_nesvnic = nesvnic;
 	}
 
-	if (nesvnic->of_device_registered) {
-		nesdev->iw_status = 1;
-		nesdev->nesadapter->send_term_ok = 1;
-		nes_port_ibevent(nesvnic);
-	}
-
 	if (first_nesvnic->linkup) {
 		/* Enable network packets */
 		nesvnic->linkup = 1;
 		netif_start_queue(netdev);
 		netif_carrier_on(netdev);
 	}
+
+	spin_lock_irqsave(&nesvnic->port_ibevent_lock, flags);
+	if (nesvnic->of_device_registered) {
+		nesdev->nesadapter->send_term_ok = 1;
+		if (nesvnic->linkup == 1) {
+			if (nesdev->iw_status == 0) {
+				nesdev->iw_status = 1;
+				nes_port_ibevent(nesvnic);
+			}
+		} else {
+			nesdev->iw_status = 0;
+		}
+	}
+	spin_unlock_irqrestore(&nesvnic->port_ibevent_lock, flags);
+
 	napi_enable(&nesvnic->napi);
 	nesvnic->netdev_open = 1;
 
···
 	u32 nic_active;
 	struct nes_vnic *first_nesvnic = NULL;
 	struct list_head *list_pos, *list_temp;
+	unsigned long flags;
 
 	nes_debug(NES_DBG_SHUTDOWN, "nesvnic=%p, nesdev=%p, netdev=%p %s\n",
 			nesvnic, nesdev, netdev, netdev->name);
···
 	nic_active &= nic_active_mask;
 	nes_write_indexed(nesdev, NES_IDX_NIC_BROADCAST_ON, nic_active);
 
-
+	spin_lock_irqsave(&nesvnic->port_ibevent_lock, flags);
 	if (nesvnic->of_device_registered) {
 		nesdev->nesadapter->send_term_ok = 0;
 		nesdev->iw_status = 0;
-		nes_port_ibevent(nesvnic);
+		if (nesvnic->linkup == 1)
+			nes_port_ibevent(nesvnic);
 	}
+	del_timer_sync(&nesvnic->event_timer);
+	nesvnic->event_timer.function = NULL;
+	spin_unlock_irqrestore(&nesvnic->port_ibevent_lock, flags);
+
 	nes_destroy_nic_qp(nesvnic);
 
 	nesvnic->netdev_open = 0;
···
 		nesvnic->rdma_enabled = 0;
 	}
 	nesvnic->nic_cq.cq_number = nesvnic->nic.qp_id;
+	init_timer(&nesvnic->event_timer);
+	nesvnic->event_timer.function = NULL;
 	spin_lock_init(&nesvnic->tx_lock);
+	spin_lock_init(&nesvnic->port_ibevent_lock);
 	nesdev->netdev[nesdev->netdev_count] = netdev;
 
 	nes_debug(NES_DBG_INIT, "Adding nesvnic (%p) to the adapters nesvnic_list for MAC%d.\n",

drivers/infiniband/hw/nes/nes_verbs.c

···
 	return nesibdev;
 }
 
+
+/**
+ * nes_handle_delayed_event
+ */
+static void nes_handle_delayed_event(unsigned long data)
+{
+	struct nes_vnic *nesvnic = (void *) data;
+
+	if (nesvnic->delayed_event != nesvnic->last_dispatched_event) {
+		struct ib_event event;
+
+		event.device = &nesvnic->nesibdev->ibdev;
+		if (!event.device)
+			goto stop_timer;
+		event.event = nesvnic->delayed_event;
+		event.element.port_num = nesvnic->logical_port + 1;
+		ib_dispatch_event(&event);
+	}
+
+stop_timer:
+	nesvnic->event_timer.function = NULL;
+}
+
+
 void  nes_port_ibevent(struct nes_vnic *nesvnic)
 {
 	struct nes_ib_device *nesibdev = nesvnic->nesibdev;
···
 	event.device = &nesibdev->ibdev;
 	event.element.port_num = nesvnic->logical_port + 1;
 	event.event = nesdev->iw_status ? IB_EVENT_PORT_ACTIVE : IB_EVENT_PORT_ERR;
-	ib_dispatch_event(&event);
+
+	if (!nesvnic->event_timer.function) {
+		ib_dispatch_event(&event);
+		nesvnic->last_dispatched_event = event.event;
+		nesvnic->event_timer.function = nes_handle_delayed_event;
+		nesvnic->event_timer.data = (unsigned long) nesvnic;
+		nesvnic->event_timer.expires = jiffies + NES_EVENT_DELAY;
+		add_timer(&nesvnic->event_timer);
+	} else {
+		mod_timer(&nesvnic->event_timer, jiffies + NES_EVENT_DELAY);
+	}
+	nesvnic->delayed_event = event.event;
 }