i40e/i40evf: enable hardware feature head write back
The hardware supports a feature to avoid updating the descriptor
ring by marking each descriptor with a DD bit, and instead
writes a memory location with an update to where the driver
should clean up to. Enable this feature.
Change-ID: I5da4e0681f0b581a6401c950a81808792267fe57
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 661cd42..95433d4 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -2181,6 +2181,11 @@
tx_ctx.fd_ena = !!(vsi->back->flags & (I40E_FLAG_FD_SB_ENABLED |
I40E_FLAG_FD_ATR_ENABLED));
tx_ctx.timesync_ena = !!(vsi->back->flags & I40E_FLAG_PTP);
+ /* FDIR VSI tx ring can still use RS bit and writebacks */
+ if (vsi->type != I40E_VSI_FDIR)
+ tx_ctx.head_wb_ena = 1;
+ tx_ctx.head_wb_addr = ring->dma +
+ (ring->count * sizeof(struct i40e_tx_desc));
/* As part of VSI creation/update, FW allocates certain
* Tx arbitration queue sets for each TC enabled for