enic: Bug fix: try harder to fill Rx ring on skb allocation failures

[safe/jmp/linux-2.6] / drivers / net / enic / enic_main.c

diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index b4a11be..452a6b7 100644 (file)
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -1091,6 +1091,7 @@ static int enic_poll(struct napi_struct *napi, int budget)
        unsigned int rq_work_to_do = budget;
        unsigned int wq_work_to_do = -1; /* no limit */
        unsigned int  work_done, rq_work_done, wq_work_done;
+       int err;
 
        /* Service RQ (first) and WQ
         */
@@ -1114,16 +1115,19 @@ static int enic_poll(struct napi_struct *napi, int budget)
                        0 /* don't unmask intr */,
                        0 /* don't reset intr timer */);
 
-       if (rq_work_done > 0) {
+       err = vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
 
-               /* Replenish RQ
-                */
+       /* Buffer allocation failed. Stay in polling
+        * mode so we can try to fill the ring again.
+        */
 
-               vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
+       if (err)
+               rq_work_done = rq_work_to_do;
 
-       } else {
+       if (rq_work_done < rq_work_to_do) {
 
-               /* If no work done, flush all LROs and exit polling
+               /* Some work done, but not enough to stay in polling,
+                * flush all LROs and exit polling
                 */
 
                if (netdev->features & NETIF_F_LRO)
@@ -1142,6 +1146,7 @@ static int enic_poll_msix(struct napi_struct *napi, int budget)
        struct net_device *netdev = enic->netdev;
        unsigned int work_to_do = budget;
        unsigned int work_done;
+       int err;
 
        /* Service RQ
         */
@@ -1149,25 +1154,30 @@ static int enic_poll_msix(struct napi_struct *napi, int budget)
        work_done = vnic_cq_service(&enic->cq[ENIC_CQ_RQ],
                work_to_do, enic_rq_service, NULL);
 
-       if (work_done > 0) {
-
-               /* Replenish RQ
-                */
-
-               vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
-
-               /* Return intr event credits for this polling
-                * cycle.  An intr event is the completion of a
-                * RQ packet.
-                */
+       /* Return intr event credits for this polling
+        * cycle.  An intr event is the completion of a
+        * RQ packet.
+        */
 
+       if (work_done > 0)
                vnic_intr_return_credits(&enic->intr[ENIC_MSIX_RQ],
                        work_done,
                        0 /* don't unmask intr */,
                        0 /* don't reset intr timer */);
-       } else {
 
-               /* If no work done, flush all LROs and exit polling
+       err = vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
+
+       /* Buffer allocation failed. Stay in polling mode
+        * so we can try to fill the ring again.
+        */
+
+       if (err)
+               work_done = work_to_do;
+
+       if (work_done < work_to_do) {
+
+               /* Some work done, but not enough to stay in polling,
+                * flush all LROs and exit polling
                 */
 
                if (netdev->features & NETIF_F_LRO)
@@ -1350,11 +1360,13 @@ static int enic_open(struct net_device *netdev)
        }
 
        for (i = 0; i < enic->rq_count; i++) {
-               err = vnic_rq_fill(&enic->rq[i], enic->rq_alloc_buf);
-               if (err) {
+               vnic_rq_fill(&enic->rq[i], enic->rq_alloc_buf);
+               /* Need at least one buffer on ring to get going */
+               if (vnic_rq_desc_used(&enic->rq[i]) == 0) {
                        printk(KERN_ERR PFX
                                "%s: Unable to alloc receive buffers.\n",
                                netdev->name);
+                       err = -ENOMEM;
                        goto err_out_notify_unset;
                }
        }