[dpdk-dev] [PATCH v3] i40e:Fix the Descriptor Done check mechanism for i40e

[Zhe Tao]

If a descriptor the device drive is handling is the context descriptor, its type value will be 0x1.
When using the not operator ! to do the conditional check, if the expression value is zero, the device driver will consider the transaction for this descriptor has been completed,
even its DD field is still 0x1 which means NIC has not finished the operation on this descriptor. 
Use the 0xF to check the DD status to avoid the above issue happens.

Signed-off-by: Zhe Tao <zhe.tao at intel.com>
---

Patch v3 changes:
-Fix typo for the patch

Patch v2 changes:
-Fix the DD check mechanism for other functions (besides the i40e_xmit_cleanup) which use the DD bits to do conditional check

changes:
-Fix the DD check mechanism for i40e_xmit_cleanup

 drivers/net/i40e/i40e_fdir.c |  3 ++-
 drivers/net/i40e/i40e_rxtx.c | 10 ++++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/i40e/i40e_fdir.c b/drivers/net/i40e/i40e_fdir.c
index 4bf98d0..f3cb757 100644
--- a/drivers/net/i40e/i40e_fdir.c
+++ b/drivers/net/i40e/i40e_fdir.c
@@ -1110,7 +1110,8 @@ i40e_fdir_filter_programming(struct i40e_pf *pf,
 
 	for (i = 0; i < I40E_FDIR_WAIT_COUNT; i++) {
 		rte_delay_us(I40E_FDIR_WAIT_INTERVAL_US);
-		if (txdp->cmd_type_offset_bsz &
+		if ((txdp->cmd_type_offset_bsz &
+				rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) ==
 				rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))
 			break;
 	}
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 2de0ac4..7c0c684 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -574,8 +574,9 @@ i40e_xmit_cleanup(struct i40e_tx_queue *txq)
 		desc_to_clean_to = (uint16_t)(desc_to_clean_to - nb_tx_desc);
 
 	desc_to_clean_to = sw_ring[desc_to_clean_to].last_id;
-	if (!(txd[desc_to_clean_to].cmd_type_offset_bsz &
-		rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))) {
+	if ((txd[desc_to_clean_to].cmd_type_offset_bsz &
+			rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
+			rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)) {
 		PMD_TX_FREE_LOG(DEBUG, "TX descriptor %4u is not done "
 			"(port=%d queue=%d)", desc_to_clean_to,
 				txq->port_id, txq->queue_id);
@@ -1431,8 +1432,9 @@ i40e_tx_free_bufs(struct i40e_tx_queue *txq)
 	struct i40e_tx_entry *txep;
 	uint16_t i;
 
-	if (!(txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz &
-			rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)))
+	if ((txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz &
+			rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
+			rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))
 		return 0;
 
 	txep = &(txq->sw_ring[txq->tx_next_dd - (txq->tx_rs_thresh - 1)]);
-- 
1.8.4.2