2 files changed, 82 insertions, 7 deletions

diff --git a/drivers/net/spider_net.c b/drivers/net/spider_net.c
index 69005d113d4d..c99980a14203 100644
--- a/drivers/net/spider_net.c
+++ b/drivers/net/spider_net.c
@@ -1051,6 +1051,66 @@ static void show_rx_chain(struct spider_net_card *card)
 #endif
 
 /**
+ * spider_net_resync_head_ptr - Advance head ptr past empty descrs
+ *
+ * If the driver fails to keep up and empty the queue, then the
+ * hardware wil run out of room to put incoming packets. This
+ * will cause the hardware to skip descrs that are full (instead
+ * of halting/retrying). Thus, once the driver runs, it wil need
+ * to "catch up" to where the hardware chain pointer is at.
+ */
+static void spider_net_resync_head_ptr(struct spider_net_card *card)
+{
+        unsigned long flags;
+        struct spider_net_descr_chain *chain = &card->rx_chain;
+        struct spider_net_descr *descr;
+        int i, status;
+
+        /* Advance head pointer past any empty descrs */
+        descr = chain->head;
+        status = spider_net_get_descr_status(descr->hwdescr);
+
+        if (status == SPIDER_NET_DESCR_NOT_IN_USE)
+                return;
+
+        spin_lock_irqsave(&chain->lock, flags);
+
+        descr = chain->head;
+        status = spider_net_get_descr_status(descr->hwdescr);
+        for (i=0; i<chain->num_desc; i++) {
+                if (status != SPIDER_NET_DESCR_CARDOWNED) break;
+                descr = descr->next;
+                status = spider_net_get_descr_status(descr->hwdescr);
+        }
+        chain->head = descr;
+
+        spin_unlock_irqrestore(&chain->lock, flags);
+}
+
+static int spider_net_resync_tail_ptr(struct spider_net_card *card)
+{
+        struct spider_net_descr_chain *chain = &card->rx_chain;
+        struct spider_net_descr *descr;
+        int i, status;
+
+        /* Advance tail pointer past any empty and reaped descrs */
+        descr = chain->tail;
+        status = spider_net_get_descr_status(descr->hwdescr);
+
+        for (i=0; i<chain->num_desc; i++) {
+                if ((status != SPIDER_NET_DESCR_CARDOWNED) &&
+                    (status != SPIDER_NET_DESCR_NOT_IN_USE)) break;
+                descr = descr->next;
+                status = spider_net_get_descr_status(descr->hwdescr);
+        }
+        chain->tail = descr;
+
+        if ((i == chain->num_desc) || (i == 0))
+                return 1;
+        return 0;
+}
+
+/**
  * spider_net_decode_one_descr - processes an RX descriptor
  * @card: card structure
  *
@@ -1175,6 +1235,12 @@ spider_net_poll(struct net_device *netdev, int *budget)
                 }
         }
 
+        if ((packets_done == 0) && (card->num_rx_ints != 0)) {
+                no_more_packets = spider_net_resync_tail_ptr(card);
+                spider_net_resync_head_ptr(card);
+        }
+        card->num_rx_ints = 0;
+
         netdev->quota -= packets_done;
         *budget -= packets_done;
         spider_net_refill_rx_chain(card);
@@ -1421,7 +1487,11 @@ spider_net_handle_error_irq(struct spider_net_card *card, u32 status_reg)
                 if (netif_msg_intr(card) && net_ratelimit())
                         pr_err("Spider RX RAM full, incoming packets "
                                "might be discarded!\n");
-                spider_net_rx_irq_off(card);
+                /* Could happen when rx chain is full */
+                spider_net_resync_head_ptr(card);
+                spider_net_refill_rx_chain(card);
+                spider_net_enable_rxdmac(card);
+                card->num_rx_ints ++;
                 netif_rx_schedule(card->netdev);
                 show_error = 0;
                 break;
@@ -1437,12 +1507,11 @@ spider_net_handle_error_irq(struct spider_net_card *card, u32 status_reg)
         case SPIDER_NET_GDCDCEINT: /* fallthrough */
         case SPIDER_NET_GDBDCEINT: /* fallthrough */
         case SPIDER_NET_GDADCEINT:
-                if (netif_msg_intr(card) && net_ratelimit())
-                        pr_err("got descriptor chain end interrupt, "
-                               "restarting DMAC %c.\n",
-                               'D'-(i-SPIDER_NET_GDDDCEINT)/3);
+                spider_net_resync_head_ptr(card);
                 spider_net_refill_rx_chain(card);
                 spider_net_enable_rxdmac(card);
+                card->num_rx_ints ++;
+                netif_rx_schedule(card->netdev);
                 show_error = 0;
                 break;
 
@@ -1451,9 +1520,12 @@ spider_net_handle_error_irq(struct spider_net_card *card, u32 status_reg)
         case SPIDER_NET_GDCINVDINT: /* fallthrough */
         case SPIDER_NET_GDBINVDINT: /* fallthrough */
         case SPIDER_NET_GDAINVDINT:
-                /* could happen when rx chain is full */
+                /* Could happen when rx chain is full */
+                spider_net_resync_head_ptr(card);
                 spider_net_refill_rx_chain(card);
                 spider_net_enable_rxdmac(card);
+                card->num_rx_ints ++;
+                netif_rx_schedule(card->netdev);
                 show_error = 0;
                 break;
 
@@ -1546,6 +1618,7 @@ spider_net_interrupt(int irq, void *ptr)
         if (status_reg & SPIDER_NET_RXINT ) {
                 spider_net_rx_irq_off(card);
                 netif_rx_schedule(netdev);
+                card->num_rx_ints ++;
         }
         if (status_reg & SPIDER_NET_TXINT)
                 netif_rx_schedule(netdev);
@@ -2191,6 +2264,7 @@ spider_net_setup_netdev(struct spider_net_card *card)
          *              NETIF_F_HW_VLAN_FILTER */
 
         netdev->irq = card->pdev->irq;
+        card->num_rx_ints = 0;
 
         dn = pci_device_to_OF_node(card->pdev);
         if (!dn)
diff --git a/drivers/net/spider_net.h b/drivers/net/spider_net.h
index 4a1e0d28a502..b620f181227c 100644
--- a/drivers/net/spider_net.h
+++ b/drivers/net/spider_net.h
@@ -25,7 +25,7 @@
 #ifndef _SPIDER_NET_H
 #define _SPIDER_NET_H
 
-#define VERSION "2.0 A"
+#define VERSION "2.0 B"
 
 #include "sungem_phy.h"
 
@@ -461,6 +461,7 @@ struct spider_net_card {
         struct work_struct tx_timeout_task;
         atomic_t tx_timeout_task_counter;
         wait_queue_head_t waitq;
+        int num_rx_ints;
 
         /* for ethtool */
         int msg_enable;