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 <maciej.sosnowski@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

4 files changed, 83 insertions, 9 deletions

diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 1980a461c49..2b89b06ca7c 100644
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -2608,6 +2608,13 @@ static void nes_process_mac_intr(struct nes_device *nesdev, u32 mac_number)
                                                 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 {
@@ -2633,6 +2640,13 @@ static void nes_process_mac_intr(struct nes_device *nesdev, u32 mac_number)
                                                 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);
                                 }
                         }
                 }
diff --git a/drivers/infiniband/hw/nes/nes_hw.h b/drivers/infiniband/hw/nes/nes_hw.h
index 1204c3432b6..8a9ea9a4dc5 100644
--- a/drivers/infiniband/hw/nes/nes_hw.h
+++ b/drivers/infiniband/hw/nes/nes_hw.h
@@ -1193,6 +1193,8 @@ struct nes_listener {
 
 struct nes_ib_device;
 
+#define NES_EVENT_DELAY msecs_to_jiffies(100)
+
 struct nes_vnic {
         struct nes_ib_device *nesibdev;
         u64 sq_full;
@@ -1247,6 +1249,10 @@ struct nes_vnic {
         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 {
diff --git a/drivers/infiniband/hw/nes/nes_nic.c b/drivers/infiniband/hw/nes/nes_nic.c
index 5a4c3648472..81052fbcd9b 100644
--- a/drivers/infiniband/hw/nes/nes_nic.c
+++ b/drivers/infiniband/hw/nes/nes_nic.c
@@ -144,6 +144,7 @@ static int nes_netdev_open(struct net_device *netdev)
         u32 nic_active_bit;
         u32 nic_active;
         struct list_head *list_pos, *list_temp;
+        unsigned long flags;
 
         assert(nesdev != NULL);
 
@@ -233,18 +234,27 @@ static int nes_netdev_open(struct net_device *netdev)
                 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;
 
@@ -263,6 +273,7 @@ static int nes_netdev_stop(struct net_device *netdev)
         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);
@@ -315,12 +326,17 @@ static int nes_netdev_stop(struct net_device *netdev)
         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;
@@ -1750,7 +1766,10 @@ struct net_device *nes_netdev_init(struct nes_device *nesdev,
                 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",
diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c
index 99933e4e48f..26d8018c0a7 100644
--- a/drivers/infiniband/hw/nes/nes_verbs.c
+++ b/drivers/infiniband/hw/nes/nes_verbs.c
@@ -3936,6 +3936,30 @@ struct nes_ib_device *nes_init_ofa_device(struct net_device *netdev)
         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;
@@ -3944,7 +3968,18 @@ void  nes_port_ibevent(struct nes_vnic *nesvnic)
         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;
 }