cnic: Fix lost interrupt on bnx2x

We service 2 queues (kcq1 and kcq2) in cnic_service_bnx2x_bh().  If
the status block index has changed when servicing the kcq2, we must
go back and check kcq1.  The latest status block index will be used
to acknowledge the interrupt, and without looping back to check kcq1,
we may miss events on kcq1.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/cnic.c

@@ -2914,26 +2914,35 @@ static void cnic_service_bnx2x_bh(unsigned long data)
 {
 	struct cnic_dev *dev = (struct cnic_dev *) data;
 	struct cnic_local *cp = dev->cnic_priv;
-	u32 status_idx;
+	u32 status_idx, new_status_idx;
 
 	if (unlikely(!test_bit(CNIC_F_CNIC_UP, &dev->flags)))
 		return;
 
+	while (1) {
 		status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq1);
 
-	CNIC_WR16(dev, cp->kcq1.io_addr, cp->kcq1.sw_prod_idx + MAX_KCQ_IDX);
+		CNIC_WR16(dev, cp->kcq1.io_addr,
+			  cp->kcq1.sw_prod_idx + MAX_KCQ_IDX);
 
-	if (BNX2X_CHIP_IS_E2(cp->chip_id)) {
-		status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq2);
+		if (!BNX2X_CHIP_IS_E2(cp->chip_id)) {
+			cnic_ack_bnx2x_int(dev, cp->bnx2x_igu_sb_id, USTORM_ID,
+					   status_idx, IGU_INT_ENABLE, 1);
+			break;
+		}
+
+		new_status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq2);
+
+		if (new_status_idx != status_idx)
+			continue;
 
 		CNIC_WR16(dev, cp->kcq2.io_addr, cp->kcq2.sw_prod_idx +
 			  MAX_KCQ_IDX);
 
 		cnic_ack_igu_sb(dev, cp->bnx2x_igu_sb_id, IGU_SEG_ACCESS_DEF,
 				status_idx, IGU_INT_ENABLE, 1);
-	} else {
-		cnic_ack_bnx2x_int(dev, cp->bnx2x_igu_sb_id, USTORM_ID,
-				   status_idx, IGU_INT_ENABLE, 1);
+
+		break;
 	}
 }