[net-next 01/14] ixgbe: fix possible divide by zero in ixgbe_update_itr

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

From: Don Skidmore <donald.c.skidmore@intel.com>

Protect the code by bailing out of ixgbe_update_itr() when this occurs.
The next call to ixgbe_update_itr will continue to dynamically update ITR.

Signed-of-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 6225f88..9afc959 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2095,6 +2095,9 @@ static void ixgbe_update_itr(struct ixgbe_q_vector *q_vector,
 	 */
 	/* what was last interrupt timeslice? */
 	timepassed_us = q_vector->itr >> 2;
+	if (timepassed_us == 0)
+		return;
+
 	bytes_perint = bytes / timepassed_us; /* bytes/usec */
 
 	switch (itr_setting) {
-- 
1.7.11.7