i40evf: add new write-back mode
Add write-back on interrupt throttle rate timer expiration support
for the i40evf driver, when running on X722 devices.
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>
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 7a00657..7d663fb 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -252,6 +252,22 @@
tx_ring->q_vector->tx.total_bytes += total_bytes;
tx_ring->q_vector->tx.total_packets += total_packets;
+ if (tx_ring->flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+ unsigned int j = 0;
+ /* check to see if there are < 4 descriptors
+ * waiting to be written back, then kick the hardware to force
+ * them to be written back in case we stay in NAPI.
+ * In this mode on X722 we do not enable Interrupt.
+ */
+ j = i40evf_get_tx_pending(tx_ring);
+
+ if (budget &&
+ ((j / (WB_STRIDE + 1)) == 0) && (j > 0) &&
+ !test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
+ (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
+ tx_ring->arm_wb = true;
+ }
+
netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
tx_ring->queue_index),
total_packets, total_bytes);