ixgbe: use DD bit to count RX available descriptors

Signed-off-by: Intel

diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index e9eb83b..8e7cb26 100644 (file)
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -2271,29 +2271,32 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
        return 0;
 }
 
-uint32_t ixgbe_dev_rx_queue_count(struct rte_eth_dev *dev,
-                                       uint16_t rx_queue_id)
+uint32_t
+ixgbe_dev_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 {
+#define IXGBE_RXQ_SCAN_INTERVAL 4
+       volatile union ixgbe_adv_rx_desc *rxdp;
        struct igb_rx_queue *rxq;
-       uint32_t nb_pkts_available;
-       uint32_t rx_rdh;
-       uint32_t rx_id;
+       uint32_t desc = 0;
 
        if (rx_queue_id >= dev->data->nb_rx_queues) {
-           PMD_RX_LOG(DEBUG,"Invalid RX queue_id=%d\n", rx_queue_id);
-           return 0;
+               PMD_RX_LOG(ERR, "Invalid RX queue id=%d\n", rx_queue_id);
+               return 0;
        }
 
        rxq = dev->data->rx_queues[rx_queue_id];
-       rx_id = (uint16_t)((rxq->rx_tail == 0) ?
-               (rxq->nb_rx_desc - 1) : (rxq->rx_tail - 1));
-       rx_rdh = IXGBE_PCI_REG(rxq->rdh_reg_addr);
-       if (rx_rdh > rx_id) 
-           nb_pkts_available = rx_rdh - rx_id;
-       else 
-           nb_pkts_available = rx_rdh - rx_id + rxq->nb_rx_desc;
- 
-       return (nb_pkts_available);
+       rxdp = &(rxq->rx_ring[rxq->rx_tail]);
+
+       while ((desc < rxq->nb_rx_desc) &&
+               (rxdp->wb.upper.status_error & IXGBE_RXDADV_STAT_DD)) {
+               desc += IXGBE_RXQ_SCAN_INTERVAL;
+               rxdp += IXGBE_RXQ_SCAN_INTERVAL;
+               if (rxq->rx_tail + desc >= rxq->nb_rx_desc)
+                       rxdp = &(rxq->rx_ring[rxq->rx_tail +
+                               desc - rxq->nb_rx_desc]);
+       }
+
+       return desc;
 }
 
 void