From: Alexander Duyck <alexander.h.du...@linux.intel.com>

There were a couple cases where the ITR value generated via the adaptive
ITR scheme could exceed 126. This resulted in the value becoming either 0
or something less than 10. Switching back and forth between a value less
than 10 and a value greater than 10 can cause issues as certain hardware
features such as RSC to not function well when the ITR value has dropped
that low.

Reported-by: Gregg Leventhal <glevent...@janestreet.com>
Signed-off-by: Alexander Duyck <alexander.h.du...@linux.intel.com>
Tested-by: Andrew Bowers <andrewx.bow...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c 
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index dc034f4e8cf6..a5398b691aa8 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2623,7 +2623,7 @@ static void ixgbe_update_itr(struct ixgbe_q_vector 
*q_vector,
                /* 16K ints/sec to 9.2K ints/sec */
                avg_wire_size *= 15;
                avg_wire_size += 11452;
-       } else if (avg_wire_size <= 1980) {
+       } else if (avg_wire_size < 1968) {
                /* 9.2K ints/sec to 8K ints/sec */
                avg_wire_size *= 5;
                avg_wire_size += 22420;
@@ -2656,6 +2656,8 @@ static void ixgbe_update_itr(struct ixgbe_q_vector 
*q_vector,
        case IXGBE_LINK_SPEED_2_5GB_FULL:
        case IXGBE_LINK_SPEED_1GB_FULL:
        case IXGBE_LINK_SPEED_10_FULL:
+               if (avg_wire_size > 8064)
+                       avg_wire_size = 8064;
                itr += DIV_ROUND_UP(avg_wire_size,
                                    IXGBE_ITR_ADAPTIVE_MIN_INC * 64) *
                       IXGBE_ITR_ADAPTIVE_MIN_INC;
-- 
2.21.0

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