enic: bug fix: return notify intr credits

Return notify intr credits after notify intr from firmware.  This is
especially important for legacy PCI intr mode, where not returning
credits would cause PBA to remain asserted which would get us right
back into the ISR.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/enic/enic.h

@@ -33,7 +33,7 @@
 
 #define DRV_NAME		"enic"
 #define DRV_DESCRIPTION		"Cisco 10G Ethernet Driver"
-#define DRV_VERSION		"1.0.0.648"
+#define DRV_VERSION		"1.0.0.933"
 #define DRV_COPYRIGHT		"Copyright 2008 Cisco Systems, Inc"
 #define PFX			DRV_NAME ": "
 

drivers/net/enic/enic_main.c

@@ -400,10 +400,13 @@ static irqreturn_t enic_isr_legacy(int irq, void *data)
 		return IRQ_NONE;	/* not our interrupt */
 	}
 
-	if (ENIC_TEST_INTR(pba, ENIC_INTX_NOTIFY))
+	if (ENIC_TEST_INTR(pba, ENIC_INTX_NOTIFY)) {
+		vnic_intr_return_all_credits(&enic->intr[ENIC_INTX_NOTIFY]);
 		enic_notify_check(enic);
+	}
 
 	if (ENIC_TEST_INTR(pba, ENIC_INTX_ERR)) {
+		vnic_intr_return_all_credits(&enic->intr[ENIC_INTX_ERR]);
 		enic_log_q_error(enic);
 		/* schedule recovery from WQ/RQ error */
 		schedule_work(&enic->reset);
@@ -476,6 +479,8 @@ static irqreturn_t enic_isr_msix_err(int irq, void *data)
 {
 	struct enic *enic = data;
 
+	vnic_intr_return_all_credits(&enic->intr[ENIC_MSIX_ERR]);
+
 	enic_log_q_error(enic);
 
 	/* schedule recovery from WQ/RQ error */
@@ -488,8 +493,8 @@ static irqreturn_t enic_isr_msix_notify(int irq, void *data)
 {
 	struct enic *enic = data;
 
+	vnic_intr_return_all_credits(&enic->intr[ENIC_MSIX_NOTIFY]);
 	enic_notify_check(enic);
-	vnic_intr_unmask(&enic->intr[ENIC_MSIX_NOTIFY]);
 
 	return IRQ_HANDLED;
 }
@@ -616,7 +621,7 @@ static inline void enic_queue_wq_skb(struct enic *enic,
 			vlan_tag_insert, vlan_tag);
 }
 
-/* netif_tx_lock held, process context with BHs disabled */
+/* netif_tx_lock held, process context with BHs disabled, or BH */
 static int enic_hard_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct enic *enic = netdev_priv(netdev);
@@ -1069,7 +1074,7 @@ static int enic_poll(struct napi_struct *napi, int budget)
 			lro_flush_all(&enic->lro_mgr);
 
 		napi_complete(napi);
-		vnic_intr_unmask(&enic->intr[ENIC_MSIX_RQ]);
+		vnic_intr_unmask(&enic->intr[ENIC_INTX_WQ_RQ]);
 	}
 
 	return rq_work_done;
@@ -1095,9 +1100,9 @@ static int enic_poll_msix(struct napi_struct *napi, int budget)
 
 		vnic_rq_fill(&enic->rq[0], enic_rq_alloc_buf);
 
-		/* Accumulate intr event credits for this polling
+		/* Return intr event credits for this polling
 		 * cycle.  An intr event is the completion of a
-		 * a WQ or RQ packet.
+		 * RQ packet.
 		 */
 
 		vnic_intr_return_credits(&enic->intr[ENIC_MSIX_RQ],

drivers/net/enic/vnic_intr.h

@@ -76,6 +76,20 @@ static inline void vnic_intr_return_credits(struct vnic_intr *intr,
 	iowrite32(int_credit_return, &intr->ctrl->int_credit_return);
 }
 
+static inline unsigned int vnic_intr_credits(struct vnic_intr *intr)
+{
+	return ioread32(&intr->ctrl->int_credits);
+}
+
+static inline void vnic_intr_return_all_credits(struct vnic_intr *intr)
+{
+	unsigned int credits = vnic_intr_credits(intr);
+	int unmask = 1;
+	int reset_timer = 1;
+
+	vnic_intr_return_credits(intr, credits, unmask, reset_timer);
+}
+
 static inline u32 vnic_intr_legacy_pba(u32 __iomem *legacy_pba)
 {
 	/* read PBA without clearing */