[dpdk-dev] [PATCH 4/6] net/e1000: implement descriptor status API (em)
Lu, Wenzhuo
wenzhuo.lu at intel.com
Thu Mar 2 02:22:25 CET 2017
Hi Oliver,
> -----Original Message-----
> From: Olivier Matz [mailto:olivier.matz at 6wind.com]
> Sent: Thursday, March 2, 2017 1:19 AM
> To: dev at dpdk.org; thomas.monjalon at 6wind.com; Ananyev, Konstantin; Lu,
> Wenzhuo; Zhang, Helin; Wu, Jingjing; adrien.mazarguil at 6wind.com;
> nelio.laranjeiro at 6wind.com
> Cc: Yigit, Ferruh; Richardson, Bruce
> Subject: [PATCH 4/6] net/e1000: implement descriptor status API (em)
>
> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> +int
> +eth_em_tx_descriptor_status(struct rte_eth_dev *dev, uint16_t tx_queue_id,
> + uint16_t offset)
> +{
> + volatile uint8_t *status;
> + struct em_tx_queue *txq;
> + uint32_t desc;
> +
> + txq = dev->data->tx_queues[tx_queue_id];
> + if (unlikely(offset >= txq->nb_tx_desc))
> + return -EINVAL;
> +
> + desc = txq->tx_tail + offset;
> + /* go to next desc that has the RS bit */
> + desc = ((desc + txq->tx_rs_thresh - 1) / txq->tx_rs_thresh) *
> + txq->tx_rs_thresh;
The descriptor may be changed here. So the return value may not be for the offset one. Why?
> + status = &txq->tx_ring[desc].upper.fields.status;
> + if (*status & E1000_TXD_STAT_DD)
> + return RTE_ETH_TX_DESC_DONE;
> +
> + return RTE_ETH_TX_DESC_FULL;
> +}
> +
> void
> em_dev_clear_queues(struct rte_eth_dev *dev) {
> --
> 2.8.1
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