From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 82ECF326C for ; Tue, 20 Nov 2018 07:13:35 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Nov 2018 22:13:34 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,255,1539673200"; d="scan'208";a="109727493" Received: from wuyanglong.sh.intel.com ([10.67.111.136]) by orsmga001.jf.intel.com with ESMTP; 19 Nov 2018 22:13:32 -0800 From: Yanglong Wu To: dev@dpdk.org Cc: qi.z.zhang@intel.com, jingjing.wu@intel.com, Yanglong Wu Date: Tue, 20 Nov 2018 13:59:21 +0800 Message-Id: <20181120055921.8209-1-yanglong.wu@intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181116023220.114517-1-yanglong.wu@intel.com> References: <20181116023220.114517-1-yanglong.wu@intel.com> Subject: [dpdk-dev] [PATCH v2] net/ixgbe: fix TDH register setting issue X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Nov 2018 06:13:36 -0000 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. cc stable@dpdk.org Signed-off-by: Yanglong Wu --- v2: change fix commit --- 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