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 C4514CD98E1 for ; Tue, 16 Jun 2026 12:21:38 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 2160340E42; Tue, 16 Jun 2026 14:21:17 +0200 (CEST) Received: from smtpbgbr2.qq.com (smtpbgbr2.qq.com [54.207.22.56]) by mails.dpdk.org (Postfix) with ESMTP id 64F4A40E13; Tue, 16 Jun 2026 14:21:11 +0200 (CEST) X-QQ-mid: esmtpsz20t1781612466t1195fe80 X-QQ-Originating-IP: AbA6D0RxBUOlgoyBZL4XTv4jcM/zbaEr/jV9VgBp7Og= Received: from DSK-zaiyuwang.trustnetic.com ( [183.157.22.210]) by bizesmtp.qq.com (ESMTP) with id ; Tue, 16 Jun 2026 20:21:04 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 7881421196719803942 EX-QQ-RecipientCnt: 4 From: Zaiyu Wang To: dev@dpdk.org Cc: Zaiyu Wang , stable@dpdk.org, Jiawen Wu Subject: [PATCH v6 05/21] net/txgbe: fix inaccuracy in Tx rate limiting Date: Tue, 16 Jun 2026 20:20:13 +0800 Message-Id: <20260616122030.9688-6-zaiyuwang@trustnetic.com> X-Mailer: git-send-email 2.21.0.windows.1 In-Reply-To: <20260616122030.9688-1-zaiyuwang@trustnetic.com> References: <20260423034024.14404-1-zaiyuwang@trustnetic.com> <20260616122030.9688-1-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: OVMqbsUyNYbuKe09/eg7d0wreR1jPxENCAEXrZLnVpCpmUH2tylmVc3j 4DoYYhO5umSRBaJCpL/61VfaPw6dQra3RSYdX1hPoF56rMF0mGnsGw7sfgvWm/G66zFhdSW D120yYk2isS6hNZArtJQqrS2D6RKAm3fioCSncsx3bTqgbiTtYEdCJM1VNrJIJas/eVwquN 4Ab9bPsEqFhE7ntUsnoiqt/n8uqxv849OmURLeqcvSrKPzssCHXuIohrvySny70wC9H6Q33 8aZxyThJKIIMH1xMoE6DIlKkEYU25YaNTVf6hZ7oCIiqnuOAtbXhrJmrJIUpDHXvy7bvSTJ tgVsjR35Uen9i6a8DyiqZXDrPo8TUqnJ2QYqkAOfMKm7mYO4AD8sMGgN+IhrAGm5ZbG/bLx McuZaddKUXqQMKeirgcuUxMPdz6RG1DWbKzPQx0b5I6gMCmYIRN6u2Fpw6aRc4r04l8RuCy VYxWZC80AhKnhiiV37EWZi0kADAKZJaJ/pmMIHEeumG2D2se45PLoo49nX1Oo9orh4A906K wfqzBWzBuRdUGdl6qqow1BUUZ++2WVB29F5M/CU6HMMnAsFc+BIIgO2Hy5v+S8CR7+QaftA jEalec3pcR/GP43ji9wtUbb6HR0LqJhKhoZhb0FC3iQ6Z8MB6vQYgY2iEMsNcAdvEs2ad+W HpUVvDaUmK//5wrnBjNdmgCDsPKdxG27CPQyGBKWe1c92CWKDXsoswc+Hyt8PjNsY83gisO xuFzIQ4rDMaLL9oSPnPW2hIGVbUJf2hXBrWdQbFXOI5Czse1o7zDJ2KPHGlVYNulifW1AlC i7SjAaygF4MO/zYPB2mZH+c6380Phv3WQgteFC/inXmeZxWtG2LLlXXcJbTfpN6djnzfo7k Ol/1tYlcZ2+Aw1T+OkPBLvJmmaz3gogH/cntkY4GSzQ7QbVS05BovQ/m81l8ZAwkQsp5bWz gPxLgIDZ7GDaqW19ajFxbDPoSWjT0dvp/n6U3NA8soCHb5HkcZmFaLVPTK0bjS+knzhBr1Z JZ+JizRE60pnrnwxNh90f/6UQppwdv23+zXMKZ7W6lnHzUnBh2qcH8NN3sZsMOCWS8SiiS4 HCKBmw+7avP X-QQ-XMRINFO: NyFYKkN4Ny6FuXrnB5Ye7Aabb3ujjtK+gg== 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 779874aac9..099341b5ab 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