i40e: do not flush after re-enabling interrupts

Hot path doesn't need read-flush after interrupt enable, and this
flush really causes a lot of extra cpu utilization.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

2 files changed, 2 insertions, 3 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index fbe7fe2914a9..69ed8014afbd 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -2560,7 +2560,7 @@ void i40e_irq_dynamic_enable(struct i40e_vsi *vsi, int vector)
               I40E_PFINT_DYN_CTLN_CLEARPBA_MASK |
               (I40E_ITR_NONE << I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT);
         wr32(hw, I40E_PFINT_DYN_CTLN(vector - 1), val);
-        i40e_flush(hw);
+        /* skip the flush */
 }
 
 /**
@@ -2709,6 +2709,7 @@ static int i40e_vsi_enable_irq(struct i40e_vsi *vsi)
                 i40e_irq_dynamic_enable_icr0(pf);
         }
 
+        i40e_flush(&pf->hw);
         return 0;
 }
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index dc89e72fd0f4..fbc40cd29d23 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -559,8 +559,6 @@ static void i40e_update_dynamic_itr(struct i40e_q_vector *q_vector)
         i40e_set_new_dynamic_itr(&q_vector->tx);
         if (old_itr != q_vector->tx.itr)
                 wr32(hw, reg_addr, q_vector->tx.itr);
-
-        i40e_flush(hw);
 }
 
 /**