From patchwork Mon Nov 6 06:31:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sasha Neftin X-Patchwork-Id: 834472 X-Patchwork-Delegate: jeffrey.t.kirsher@intel.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=osuosl.org (client-ip=140.211.166.136; helo=silver.osuosl.org; envelope-from=intel-wired-lan-bounces@osuosl.org; receiver=) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yVjQf20FBz9s4q for ; Mon, 6 Nov 2017 17:32:09 +1100 (AEDT) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 3C639304EA; Mon, 6 Nov 2017 06:32:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id URjmm9g-EnRu; Mon, 6 Nov 2017 06:32:05 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by silver.osuosl.org (Postfix) with ESMTP id 7463B303F2; Mon, 6 Nov 2017 06:32:05 +0000 (UTC) X-Original-To: intel-wired-lan@lists.osuosl.org Delivered-To: intel-wired-lan@lists.osuosl.org Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by ash.osuosl.org (Postfix) with ESMTP id 4F78F1C0000 for ; Mon, 6 Nov 2017 06:32:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 3E4F7303F2 for ; Mon, 6 Nov 2017 06:32:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5kO8XIsYuMGA for ; Mon, 6 Nov 2017 06:32:03 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by silver.osuosl.org (Postfix) with ESMTPS id 4DB262EE8F for ; Mon, 6 Nov 2017 06:32:03 +0000 (UTC) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP; 05 Nov 2017 22:32:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,351,1505804400"; d="scan'208";a="171909307" Received: from hostname.iil.intel.com (HELO ccdlinuxdev01.iil.intel.com) ([143.185.162.145]) by fmsmga005.fm.intel.com with ESMTP; 05 Nov 2017 22:32:00 -0800 From: Sasha Neftin To: jeffrey.t.kirsher@intel.com, sasha.neftin@intel.com, intel-wired-lan@lists.osuosl.org, raanan.avargil@intel.com, alexander.h.duyck@intel.com, dima.ruinskiy@intel.com Date: Mon, 6 Nov 2017 08:31:59 +0200 Message-Id: <20171106063159.32289-1-sasha.neftin@intel.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Subject: [Intel-wired-lan] [PATCH v2 1/1] e1000e: fix buffer overrun while the I219 is processing DMA transactions X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" Description: Intel® 100/200 Series Chipset platforms reduced the round-trip latency for the LAN Controller DMA accesses, causing in some high performance cases a buffer overrun while the I219 LAN Connected Device is processing the DMA transactions. I219LM and I219V devices can fall into unrecovered Tx hang under very stressfully UDP traffic and multiple reconnection of Ethernet cable. This Tx hang of the LAN Controller is only recovered if the system is rebooted. Slightly slow down DMA access by reducing the number of outstanding requests. This workaround could have an impact on TCP traffic performance on the platform. Disabling TSO eliminates performance loss for TCP traffic without a noticeable impact on CPU performance. Please, refer to I218/I219 specification update: https://www.intel.com/content/www/us/en/embedded/products/networking/ ethernet-connection-i218-family-documentation.html Signed-off-by: Sasha Neftin Reviewed-by: Alexander H Duyck Reviewed-by: Dima Ruinskiy Reviewed-by: Raanan Avargil Tested-by: Aaron Brown --- drivers/net/ethernet/intel/e1000e/ich8lan.h | 3 ++- drivers/net/ethernet/intel/e1000e/netdev.c | 9 ++++++--- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.h b/drivers/net/ethernet/intel/e1000e/ich8lan.h index 67163ca898ba..e23d8da9b15b 100644 --- a/drivers/net/ethernet/intel/e1000e/ich8lan.h +++ b/drivers/net/ethernet/intel/e1000e/ich8lan.h @@ -113,7 +113,8 @@ #define NVM_SIZE_MULTIPLIER 4096 /*multiplier for NVMS field */ #define E1000_FLASH_BASE_ADDR 0xE000 /*offset of NVM access regs */ #define E1000_CTRL_EXT_NVMVS 0x3 /*NVM valid sector */ -#define E1000_TARC0_CB_MULTIQ_3_REQ (1 << 28 | 1 << 29) +#define E1000_TARC0_CB_MULTIQ_3_REQ 0x30000000 +#define E1000_TARC0_CB_MULTIQ_2_REQ 0x20000000 #define PCIE_ICH8_SNOOP_ALL PCIE_NO_SNOOP_ALL #define E1000_ICH_RAR_ENTRIES 7 diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index f2f49239b015..9f18d39bdc8f 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3034,9 +3034,12 @@ static void e1000_configure_tx(struct e1000_adapter *adapter) ew32(IOSFPC, reg_val); reg_val = er32(TARC(0)); - /* SPT and KBL Si errata workaround to avoid Tx hang */ - reg_val &= ~BIT(28); - reg_val |= BIT(29); + /* SPT and KBL Si errata workaround to avoid Tx hang. + * Dropping the number of outstanding requests from + * 3 to 2 in order to avoid a buffer overrun. + */ + reg_val &= ~E1000_TARC0_CB_MULTIQ_3_REQ; + reg_val |= E1000_TARC0_CB_MULTIQ_2_REQ; ew32(TARC(0), reg_val); } }