From: Alexander Duyck alexander.h.duyck@linux.intel.com
commit 377228accbbb8b9738f615d791aa803f41c067e0 upstream.
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.
CC: stable@vger.kernel.org Fixes: b4ded8327fea ("ixgbe: Update adaptive ITR algorithm") Reported-by: Gregg Leventhal gleventhal@janestreet.com Signed-off-by: Alexander Duyck alexander.h.duyck@linux.intel.com Tested-by: Andrew Bowers andrewx.bowers@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -2626,7 +2626,7 @@ adjust_by_size: /* 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; @@ -2659,6 +2659,8 @@ adjust_by_size: 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;