net/ice: fix performance with writeback policy

Apply the same fix that for iavf to DCF
commit ead06572bd8f ("net/iavf: fix performance with writeback policy")

Fixes: 4b0d391f0eab ("net/ice: add queue config in DCF")
Cc: stable@dpdk.org
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Tested-by: Lijuan Tu <lijuan.tu@intel.com>

diff --git a/drivers/net/ice/ice_dcf_ethdev.c b/drivers/net/ice/ice_dcf_ethdev.c
index 94c6a6e..f510bad 100644 (file)
--- a/drivers/net/ice/ice_dcf_ethdev.c
+++ b/drivers/net/ice/ice_dcf_ethdev.c
@@ -178,10 +178,15 @@ ice_dcf_config_rx_queues_irqs(struct rte_eth_dev *dev,
                    VIRTCHNL_VF_OFFLOAD_WB_ON_ITR) {
                        /* If WB_ON_ITR supports, enable it */
                        hw->msix_base = IAVF_RX_VEC_START;
+                       /* Set the ITR for index zero, to 2us to make sure that
+                        * we leave time for aggregation to occur, but don't
+                        * increase latency dramatically.
+                        */
                        IAVF_WRITE_REG(&hw->avf,
                                       IAVF_VFINT_DYN_CTLN1(hw->msix_base - 1),
-                                      IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK |
-                                      IAVF_VFINT_DYN_CTLN1_WB_ON_ITR_MASK);
+                                      (0 << IAVF_VFINT_DYN_CTLN1_ITR_INDX_SHIFT) |
+                                      IAVF_VFINT_DYN_CTLN1_WB_ON_ITR_MASK |
+                                      (2UL << IAVF_VFINT_DYN_CTLN1_INTERVAL_SHIFT));
                } else {
                        /* If no WB_ON_ITR offload flags, need to set
                         * interrupt for descriptor write back.