i40e: Do not disable queues in the Legacy/MSI Interrupt handler

Orabug: 22342532

The queues should never be enabled/disabled in the interrupt handler,
ICR0 interrupt enable should be the only thing that needs to be
dynamically changed in the handler.

This patch fixes that. Without this patch X722 platforms were
seeing weird ping timings when in Legacy mode since it takes
a whole lot of time for the HW/FW to re-enable queues.

Change-ID: If065afc45d81c5a19d4a94a00cd5b8f61cefc40c
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit a16ae2d59c290b0c545edb9bf41ac9cf88352ee0)
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 883a18097713ec651452add18605d4d4cb30c141..398e148a91a6a5f636a7b1854364e0485f951954 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3433,16 +3433,12 @@ static irqreturn_t i40e_intr(int irq, void *data)
                struct i40e_vsi *vsi = pf->vsi[pf->lan_vsi];
                struct i40e_q_vector *q_vector = vsi->q_vectors[0];
 
-               /* temporarily disable queue cause for NAPI processing */
-               u32 qval = rd32(hw, I40E_QINT_RQCTL(0));
-
-               qval &= ~I40E_QINT_RQCTL_CAUSE_ENA_MASK;
-               wr32(hw, I40E_QINT_RQCTL(0), qval);
-
-               qval = rd32(hw, I40E_QINT_TQCTL(0));
-               qval &= ~I40E_QINT_TQCTL_CAUSE_ENA_MASK;
-               wr32(hw, I40E_QINT_TQCTL(0), qval);
-
+               /* We do not have a way to disarm Queue causes while leaving
+                * interrupt enabled for all other causes, ideally
+                * interrupt should be disabled while we are in NAPI but
+                * this is not a performance path and napi_schedule()
+                * can deal with rescheduling.
+                */
                if (!test_bit(__I40E_DOWN, &pf->state))
                        napi_schedule_irqoff(&q_vector->napi);
        }

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 05f7b90d6f33d84ae31f14a5916a228d419cc614..53f634074bd0f3b37044dbb82a478958eb52d4f5 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2050,19 +2050,6 @@ tx_only:
        if (vsi->back->flags & I40E_FLAG_MSIX_ENABLED) {
                i40e_update_enable_itr(vsi, q_vector);
        } else { /* Legacy mode */
-               struct i40e_hw *hw = &vsi->back->hw;
-               /* We re-enable the queue 0 cause, but
-                * don't worry about dynamic_enable
-                * because we left it on for the other
-                * possible interrupts during napi
-                */
-               u32 qval = rd32(hw, I40E_QINT_RQCTL(0)) |
-                          I40E_QINT_RQCTL_CAUSE_ENA_MASK;
-
-               wr32(hw, I40E_QINT_RQCTL(0), qval);
-               qval = rd32(hw, I40E_QINT_TQCTL(0)) |
-                      I40E_QINT_TQCTL_CAUSE_ENA_MASK;
-               wr32(hw, I40E_QINT_TQCTL(0), qval);
                i40e_irq_dynamic_enable_icr0(vsi->back, false);
        }
        return 0;