From: Yanglong Wu <yanglong.wu@intel.com>
To: dev@dpdk.org
Cc: qi.z.zhang@intel.com, jingjing.wu@intel.com,
stephen1.byrne@intel.com, Yanglong Wu <yanglong.wu@intel.com>
Subject: [dpdk-dev] [PATCH] net/ixgbe: fix TDH register setting issue
Date: Fri, 16 Nov 2018 10:32:20 +0800 [thread overview]
Message-ID: <20181116023220.114517-1-yanglong.wu@intel.com> (raw)
The only time that software should write to the TDH register
is after a reset (hardware reset or CTRL.RST) and
before enabling the transmit function (TXDCTL.ENABLE).
If software were to write to this register while the transmit
function was enabled, the on-chip descriptor buffers might
be invalidated and the hardware could become confused.
Fixes: a8cdaf0964f7 ("net/ixgbe: remove redundant queue id checks")
Signed-off-by: Yanglong Wu <yanglong.wu@intel.com>
---
drivers/net/ixgbe/ixgbe_rxtx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index 2f0262ae1..ddc7efa87 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -5264,6 +5264,7 @@ ixgbe_dev_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id)
hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
txq = dev->data->tx_queues[tx_queue_id];
+ IXGBE_WRITE_REG(hw, IXGBE_TDH(txq->reg_idx), 0);
txdctl = IXGBE_READ_REG(hw, IXGBE_TXDCTL(txq->reg_idx));
txdctl |= IXGBE_TXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(txq->reg_idx), txdctl);
@@ -5281,7 +5282,6 @@ ixgbe_dev_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id)
tx_queue_id);
}
rte_wmb();
- IXGBE_WRITE_REG(hw, IXGBE_TDH(txq->reg_idx), 0);
IXGBE_WRITE_REG(hw, IXGBE_TDT(txq->reg_idx), 0);
dev->data->tx_queue_state[tx_queue_id] = RTE_ETH_QUEUE_STATE_STARTED;
--
2.11.0
next reply other threads:[~2018-11-16 2:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-16 2:32 Yanglong Wu [this message]
2018-11-16 19:51 ` Zhang, Qi Z
2018-11-20 2:11 ` Wu, Yanglong
2018-11-20 6:02 ` Zhang, Qi Z
2018-11-20 5:59 ` [dpdk-dev] [PATCH v2] " Yanglong Wu
2018-11-20 19:49 ` Zhang, Qi Z
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