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 3D5AACD98E2 for ; Wed, 17 Jun 2026 08:15:16 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 00A7740DD1; Wed, 17 Jun 2026 10:14:57 +0200 (CEST) Received: from smtpbgbr1.qq.com (smtpbgbr1.qq.com [54.207.19.206]) by mails.dpdk.org (Postfix) with ESMTP id 19C8440A73; Wed, 17 Jun 2026 10:14:52 +0200 (CEST) X-QQ-mid: zesmtpgz4t1781684089t3883b9d6 X-QQ-Originating-IP: BB8ZjwmlS08MXLRokL/DevIv55sOmYPKsMrHrRN4VcM= Received: from DSK-zaiyuwang.trustnetic.com ( [183.157.22.210]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 17 Jun 2026 16:14:48 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 14888437388638613329 EX-QQ-RecipientCnt: 4 From: Zaiyu Wang To: dev@dpdk.org Cc: Zaiyu Wang , stable@dpdk.org, Jiawen Wu Subject: [PATCH v8 05/21] net/txgbe: fix inaccuracy in Tx rate limiting Date: Wed, 17 Jun 2026 16:12:52 +0800 Message-Id: <20260617081309.19124-6-zaiyuwang@trustnetic.com> X-Mailer: git-send-email 2.21.0.windows.1 In-Reply-To: <20260617081309.19124-1-zaiyuwang@trustnetic.com> References: <20260423034024.14404-1-zaiyuwang@trustnetic.com> <20260617081309.19124-1-zaiyuwang@trustnetic.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: zesmtpgz:trustnetic.com:qybglogicsvrsz:qybglogicsvrsz3b-0 X-QQ-XMAILINFO: MKijbibGp4YDE15FGCSMsyHjFxe795PfhllvyOPPtonlmMPcaGUU4piY ZgT+ICW9ZhM77/Y085eP64NoKF+llkmK5H6h32seioaD+YP5aoOnXOfnvuWYq6r7HVtGO3q Mn1Qr9YiQjGqgN0UOi08JXY3iools62h/of7QlT6SuFmcLIXu74xGTjRuvTT7TjBQaKJoZw UGdyQT7/PQ/aEFOcm8gvQt7n5TFrGCZLSJad1kqw2z8xgD8GY5CDyG3uH7TVTOAWGSPerdt Jw2yUlauJ20L6hiMmcXLeHsl+yR0oba+m18QrUUqo0UclWvzv0lhFBOVmVjHJyx/jxXWBE4 u6pJ4yVSYx7MpSTQVeflxhLMZKlhAndwD2HBMvQnpx8ylYDKly+GpkUWAmpxlVfpETAxfWs +ieZ43k14kHYJcfShlOC2Dfr/5plshZv/fLhW539SIIITffyHKK0R2eyvUsWS/RfL1anMC5 yRy2RlmKwL+IYOkL7JiCgiQinI3iEE8bLiABl8XqxOnV+NerLY4330Iuxh4Xokqs45YUdg5 +PmQzTXn4kABzlV6rbQ4BoIfTg6UkvSlSuPoThFEwyMt545QzD2mKX+26JuAMmicdYmLjUq 4hKf1YVU8fXBYscuykJYQ5OrgUbgDRiyNEP/idYZCnX2CguEXxEna24/EMPa5gbaDSN1yKm 4fPhXTiWkDwMHT+eDZTM1jRoNIMw47m4z3LLFDzMKSKTQDIjvoklygnePUWaCJOPGboCmnw XeOVR5c8Cw5gINpXuwSwR9yOOOUK8LkZ43dagnuc64EhOxfpDFlehZwUp/eNqamHVOP6YtS 0juAfUeNQ6NDaFVi2ailsFTWHhLT8RbcheOM8cxJc/MO/hKJk0ahEHhSrMPex/9LET3/sSJ WqZRAsmImdMmoCB48VlnRPWeXdjB6DM5PBLNXpTy6FcNIHx1zIME+L8FMLURQ0XgJg8+fFX bfKwrlXHzkvjEh7uQXieA2ZQKhJgq2rB+deYSY7s1r1BJq0MTaf3ShWL/t4HhEVuc8+rchS 5vxrWuILbEPEzUieTVq5mmOBpc+ssOphCDfvbUM7KpED0TTa19VyHgf6/EBuvdCZ5hM8vt8 2VX5fl/uAOypKv4Wlw5eRnKBLtsT1mewA== X-QQ-XMRINFO: OWPUhxQsoeAVwkVaQIEGSKwwgKCxK/fD5g== 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