[PATCH] ixgbevf: fix possible divide by zero in ixgbevf_update_itr

[PATCH] ixgbevf: fix possible divide by zero in ixgbevf_update_itr

[Young Xiao]

The next call to ixgbevf_update_itr will continue to dynamically
update ITR.

Copy from commit bdbeefe8ea8c ("ixgbe: fix possible divide by zero in
ixgbe_update_itr")

Signed-off-by: Young Xiao <92siuyang@gmail.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index d189ed2..d2b41f9 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -1423,6 +1423,9 @@ static void ixgbevf_update_itr(struct ixgbevf_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) {
-- 
2.7.4

RE: [Intel-wired-lan] [PATCH] ixgbevf: fix possible divide by zero in ixgbevf_update_itr

[Bowers, AndrewX]

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Young Xiao
> Sent: Tuesday, May 28, 2019 4:58 AM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; davem@davemloft.net;
> intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: Young Xiao <92siuyang@gmail.com>
> Subject: [Intel-wired-lan] [PATCH] ixgbevf: fix possible divide by zero in
> ixgbevf_update_itr
> 
> The next call to ixgbevf_update_itr will continue to dynamically update ITR.
> 
> Copy from commit bdbeefe8ea8c ("ixgbe: fix possible divide by zero in
> ixgbe_update_itr")
> 
> Signed-off-by: Young Xiao <92siuyang@gmail.com>
> ---
>  drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 3 +++
>  1 file changed, 3 insertions(+)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>