i40e: fix possible compiler warning in xsk TX path

With certain gcc versions, it was possible to get the warning
"'tx_desc' may be used uninitialized in this function" for the
i40e_xmit_zc. This was not possible, however this commit simplifies
the code path so that this warning is no longer emitted.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 94947a826bc3adf532536ffd778da5d0e5a19964..41ca7e1310bc0f8d1085ac88322c2748fc461ba7 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -668,9 +668,8 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
  **/
 static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 {
-       unsigned int total_packets = 0;
+       struct i40e_tx_desc *tx_desc = NULL;
        struct i40e_tx_buffer *tx_bi;
-       struct i40e_tx_desc *tx_desc;
        bool work_done = true;
        dma_addr_t dma;
        u32 len;
@@ -697,14 +696,13 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
                        build_ctob(I40E_TX_DESC_CMD_ICRC
                                   | I40E_TX_DESC_CMD_EOP,
                                   0, len, 0);
-               total_packets++;
 
                xdp_ring->next_to_use++;
                if (xdp_ring->next_to_use == xdp_ring->count)
                        xdp_ring->next_to_use = 0;
        }
 
-       if (total_packets > 0) {
+       if (tx_desc) {
                /* Request an interrupt for the last frame and bump tail ptr. */
                tx_desc->cmd_type_offset_bsz |= (I40E_TX_DESC_CMD_RS <<
                                                 I40E_TXD_QW1_CMD_SHIFT);