enic: Bug fix: try harder to fill Rx ring on skb allocation failures
During dev->open(), make sure we get at least one skb on the Rx ring.
Otherwise abort the interface load. Also, if we get skb allocation
failures in NAPI poll while trying to replenish the ring, try again
later so we don't end up starving out the Rx ring completely.
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index b4a11be..452a6b7 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -1091,6 +1091,7 @@
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 @@
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 @@
struct net_device *netdev = enic->netdev;
unsigned int work_to_do = budget;
unsigned int work_done;
+ int err;
/* Service RQ
*/
@@ -1149,25 +1154,30 @@
work_done = vnic_cq_service(&enic->cq[ENIC_CQ_RQ],
work_to_do, enic_rq_service, NULL);
- if (work_done > 0) {
+ /* Return intr event credits for this polling
+ * cycle. An intr event is the completion of a
+ * RQ packet.
+ */
- /* 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.
- */
-
+ 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 @@
}
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;
}
}