[PATCH 4.14 94/94] ixgbe: check return value of napi_complete_done()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Song Liu <songliubraving@xxxxxx>

commit 4233cfe6ec4683497d7318f55ce7617e97f2e610 upstream.

The NIC driver should only enable interrupts when napi_complete_done()
returns true. This patch adds the check for ixgbe.

Cc: stable@xxxxxxxxxxxxxxx # 4.10+
Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3108,11 +3108,13 @@ int ixgbe_poll(struct napi_struct *napi,
 		return budget;
 
 	/* all work done, exit the polling mode */
-	napi_complete_done(napi, work_done);
-	if (adapter->rx_itr_setting & 1)
-		ixgbe_set_itr(q_vector);
-	if (!test_bit(__IXGBE_DOWN, &adapter->state))
-		ixgbe_irq_enable_queues(adapter, BIT_ULL(q_vector->v_idx));
+	if (likely(napi_complete_done(napi, work_done))) {
+		if (adapter->rx_itr_setting & 1)
+			ixgbe_set_itr(q_vector);
+		if (!test_bit(__IXGBE_DOWN, &adapter->state))
+			ixgbe_irq_enable_queues(adapter,
+						BIT_ULL(q_vector->v_idx));
+	}
 
 	return min(work_done, budget - 1);
 }