From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95941CDB46F for ; Mon, 22 Jun 2026 11:12:06 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 6889840662; Mon, 22 Jun 2026 13:11:49 +0200 (CEST) Received: from smtpbguseast3.qq.com (smtpbguseast3.qq.com [54.243.244.52]) by mails.dpdk.org (Postfix) with ESMTP id 10E4340663; Mon, 22 Jun 2026 13:11:46 +0200 (CEST) X-QQ-mid: esmtpsz18t1782126702t70674889 X-QQ-Originating-IP: OKuz5skzGjDycchoTxkq9UjC6cOmeJOXRkQ1t2l9RMI= Received: from DSK-zaiyuwang.trustnetic.com ( [115.204.248.247]) by bizesmtp.qq.com (ESMTP) with id ; Mon, 22 Jun 2026 19:11:41 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 16427427764133076175 EX-QQ-RecipientCnt: 4 From: Zaiyu Wang To: dev@dpdk.org Cc: Zaiyu Wang , stable@dpdk.org, Jiawen Wu Subject: [PATCH v9 05/21] net/txgbe: fix inaccuracy in Tx rate limiting Date: Mon, 22 Jun 2026 19:10:53 +0800 Message-Id: <20260622111111.21024-6-zaiyuwang@trustnetic.com> X-Mailer: git-send-email 2.21.0.windows.1 In-Reply-To: <20260622111111.21024-1-zaiyuwang@trustnetic.com> References: <20260423034024.14404-1-zaiyuwang@trustnetic.com> <20260622111111.21024-1-zaiyuwang@trustnetic.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: esmtpsz:trustnetic.com:qybglogicsvrsz:qybglogicsvrsz3b-0 X-QQ-XMAILINFO: M8Zk4Li7PoFiMnYOir9gTFUbjy1q1pgoXn4nmjResU3ERqv+NwGg9+Ry iW9K0K6+ezXE1mlcsFbLZb6hecD6Pfd3jLLGdi+vW8Ix+ziJPGEIKd8Q1IcHzuQQvWY21fc KqwLYUrBvaqgaAn4nwcIyzttvqsCcNihSep2AkEa6QdzQByTR8bwmsd58IqAS1TmtNMYfCf 9s5FaA5CLDYR51or4yQDyoXhee2ZZhor0CzqaxZdOUT/0v528mE03AMe8LnxHMXZFvVsE+N /2gERRmZj+hTXA+kPw704xpE8Lv8gaKPCDkRtcMqE/5aAMivSWRPyQFDVLFLeskeC9dF4X0 7M+pH0ainO9YAzfnrvpVYXbEBwXiUBE5hVYc0NNR78pQydBzsMQG3yeAorALNkWOPnFgMRj rzYySJn8A7MLnLjckcsti5FSFpTttdsSXCXbrmyJvch5qkt58h7LYvXMIJQwLT9RVc3S0FC uDg9EdLAPsrs1rHfPkDrzsx84mJkZ8TnyfNlXujgG9zXP0xWY/bnWoOHTrEv1vBIaV5xnVN PvP4gCL+82/APciqzvgB8QEI5l4itwVlDUIVelWPqsOzcF7Z9YEpkHxB0Rgu8sZVJL35a9v IqjrV/dHqOZi6atkbJqtERo+X7jSlFClTjx9LE/xt1Kra3/yeRVB3x3v/KBHX/D3eYuAqsb oY8aNdEOvvqO6DRRGM3uYS+6qb8c2MMSprArfhsMUditwaFb1z1NHo8Kclb8nXWXDWHKQP7 aVVR7BqFKc9p+fHOaqGK4K4TguNIMZiqBlCD2va1TNFQ4rRFNCzvZ5EW0LbBnkSzdzFQHYZ BHDpCgrjFQN1HCN37E5CsCRIBhqTDXiPuo9/iG+rUqnDcpgSwYVT1XPXmziY19DelvjVgGU RuD8yfFEp366uW8uX9q7hP/wAbbuDiYahH0Upddyp+KG1aI0MYuvK5tjHv5xuqGruQbO+E6 YTLEG3iIQJZpr2/njf1F41uV7T0GGCrat3q8RYFjy3ftD+fUse6N8JGQ09u4X9GwzzMLBnx /a5+ayOwgsDaoa4vVtL6ADuvGL8f1VqCyeOlStGo6mJLdI6R49vELO1pBmD+dR4vX1iTJ5X vPWJNv5ERPOKza2edv5wxI= X-QQ-XMRINFO: MPJ6Tf5t3I/ylTmHUqvI8+Wpn+Gzalws3A== X-QQ-RECHKSPAM: 0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Amber-lite NIC's TX rate limiting has large deviations for small packets. To address this, the following changes are made: 1. Set TDM_RL_ADJ (0x1820c) to 21B (includes 7B Ethernet preamble, 1B SFD, 1B EFD, and 12B IPG). 2) Remove the rate offset in the driver (e.g., 105 / 100, a rough compensation value from Linux kernel driver tests). After these changes, accuracy deviation for 64B packets is within ~5%, while large packets show lower deviation. Fixes: a309ab43acf3 ("net/txgbe: support Tx queue rate limiting for Amber-Lite") Cc: stable@dpdk.org Signed-off-by: Zaiyu Wang --- drivers/net/txgbe/base/txgbe_regs.h | 3 +++ drivers/net/txgbe/txgbe_ethdev.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/txgbe/base/txgbe_regs.h b/drivers/net/txgbe/base/txgbe_regs.h index 95c585a025..3d1bc88430 100644 --- a/drivers/net/txgbe/base/txgbe_regs.h +++ b/drivers/net/txgbe/base/txgbe_regs.h @@ -1670,6 +1670,9 @@ enum txgbe_5tuple_protocol { #define TXGBE_TDM_FACTOR_INT_SHIFT 16 #define TXGBE_TDM_FACTOR_FRA_SHIFT 2 +#define TXGBE_TDM_RL_ADJ 0x1820C + /* Ethernet framing overhead: 7B Ethernet preamble + 1B SFD + 1B EFD + 12B IPG */ +#define TXGBE_FRAME_OVERHEAD 21 #define TXGBE_TDM_RL_VM_IDX 0x018218 #define TXGBE_TDM_RL_VM_CFG 0x01821C #define TXGBE_TDM_RL_CFG 0x018400 diff --git a/drivers/net/txgbe/txgbe_ethdev.c b/drivers/net/txgbe/txgbe_ethdev.c index 77870f3aee..c97a7f1a4e 100644 --- a/drivers/net/txgbe/txgbe_ethdev.c +++ b/drivers/net/txgbe/txgbe_ethdev.c @@ -4314,7 +4314,6 @@ txgbe_set_queue_rate_limit(struct rte_eth_dev *dev, u16 frac; link_speed = dev->data->dev_link.link_speed; - tx_rate = tx_rate * 105 / 100; /* Calculate the rate factor values to set */ factor_int = link_speed / tx_rate; frac = (link_speed % tx_rate) * 10000 / tx_rate; @@ -4324,6 +4323,7 @@ txgbe_set_queue_rate_limit(struct rte_eth_dev *dev, factor_fra = 0; } + wr32(hw, TXGBE_TDM_RL_ADJ, TXGBE_FRAME_OVERHEAD); wr32(hw, TXGBE_TDM_RL_QUEUE_IDX, queue_idx); wr32m(hw, TXGBE_TDM_RL_QUEUE_CFG, TXGBE_TDM_FACTOR_INT_MASK, factor_int << TXGBE_TDM_FACTOR_INT_SHIFT); -- 2.21.0.windows.1