[PATCH net 1/2] i40e: Fix failure message when XDP is configured in TX only mode

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>

When starting xdpsock program in TX only mode:

samples/bpf/xdpsock -i <interface> -t

there was an error on i40e driver:

Failed to allocate some buffers on AF_XDP ZC enabled Rx ring 0 (pf_q 81)

It was caused by trying to allocate RX buffers even though
no RX buffers are available because we run in TX only mode.

Fix this by checking for number of available buffers
for RX queue when allocating buffers during XDP setup.

Fixes: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support")
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Shwetha Nagaraju <Shwetha.nagaraju@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index b5dcd15ced36..41112f92f9ef 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3555,7 +3555,7 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
 	struct i40e_hw *hw = &vsi->back->hw;
 	struct i40e_hmc_obj_rxq rx_ctx;
 	i40e_status err = 0;
-	bool ok;
+	bool ok = true;
 	int ret;
 
 	bitmap_zero(ring->state, __I40E_RING_STATE_NBITS);
@@ -3653,7 +3653,9 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
 
 	if (ring->xsk_pool) {
 		xsk_pool_set_rxq_info(ring->xsk_pool, &ring->xdp_rxq);
-		ok = i40e_alloc_rx_buffers_zc(ring, I40E_DESC_UNUSED(ring));
+		if (ring->xsk_pool->free_list_cnt)
+			ok = i40e_alloc_rx_buffers_zc(ring,
+						      I40E_DESC_UNUSED(ring));
 	} else {
 		ok = !i40e_alloc_rx_buffers(ring, I40E_DESC_UNUSED(ring));
 	}
-- 
2.35.1