From nobody Wed Nov 27 15:53:46 2024 Received: from EUR05-AM6-obe.outbound.protection.outlook.com (mail-am6eur05on2054.outbound.protection.outlook.com [40.107.22.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91F731BD516; Thu, 10 Oct 2024 09:35:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.22.54 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728552948; cv=fail; b=GGmQTu7stOtETtDyDeP0Kn1KvC1xWtJ74sNfuQKVZSWvmF7mmaxIhQX9ZFU2bqJ74tPiMyxQRB72fPPpeVbSwsFt+rj15Q5d1sdGM9uduMGnoUtNBEerhwqlJmdtnKPVUTuGKa8a9vxJy0ZEnd6Ok+VyF5+i292M8D6KWv3Dwic= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728552948; c=relaxed/simple; bh=94lZlI+yAUW8VqjbiR3ZlZhdLmdrLfQON7QWRZP+lQ0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: Content-Type:MIME-Version; b=hMqKxPwRnMDZVqH3r1GQUxzXoy26r1dn5gTETyX4fQ+LH+0B+CMNULXSngprKYdoeQTq7cxTgL8PAZx0k9DCWxD5foLe9C4WdD+KqOEnlxemhbL0HSreHUeZqhY1apGhbN8Y6Id38SvxxxPx3FD4I1LXCg8bFbYBIy9vFR7++h8= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com; spf=pass smtp.mailfrom=nxp.com; dkim=pass (2048-bit key) header.d=nxp.com header.i=@nxp.com header.b=h2G0MLFp; arc=fail smtp.client-ip=40.107.22.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nxp.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nxp.com header.i=@nxp.com header.b="h2G0MLFp" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=LtvWNa3XRYqRxBSl9cZsvpbeyPXwVuk/hsnCrN4q5jJkWJXRYtTktuUchorq+VqFfHhap5tobPjGkTjXSDNgyXtailX5BVf61q4dxCE0migHMkz0HH4gt5i7HVUMdeCjY05VHSPA7wGiYR7b+aM5gRo15CJVOxp+iB0hlb1S/1GDDpKCKWU02RzOV8dWX3qTD45XUopWJlv3c+4ghj7qvWi9ScV6QlkJY2cNGLv05dzqgwJ6WVPzoKliRG1RWSWmQWEfFGnvukGhIMwFOoC/sttnRwh1fBYPFH9EzIOvaW3DUfgRkpWpiJ8eTG58jNDvSlRuJdqbYUvx/fLtyjir2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=iEqTK5LVLzSagk7VtJOHN1FFsPC8NVFjO9XD78ydW/o=; b=x5ZafsTNniN8eQisLB7Ug/uH5LSJm+7tKvRQcgHftFuryoUeNlRYR7L9fliXaQtamCPKqp/i/U2N2Kr9aHPioiFI1loJGEz/fmp2euF+j/tCFeVkW1LeZSCsfvIoKZdsYe8R6InYUvLbMTtXDhGZS1MFXmC4Sm1WMswzpwq8knwcHHgsNWpNnUMOPNSNILwuzSsvaCH+jAd6LhZWqMyO74iXG36PFYL/ESdYt3nBMnd8zUCOWYfCepyRcByczhkDhoKGRCY9ZHJNYOGYJb09dyUe1lyWEYWz1rIn6oJnEOn61gwuFzEt2lylD/loBnEvmMEWx5oK98+artgVVhjwsQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=iEqTK5LVLzSagk7VtJOHN1FFsPC8NVFjO9XD78ydW/o=; b=h2G0MLFps3l/GpXBXG8OksAUuTeKwdLcxM9tcp82BRL/VGsj/Jjm6s+GvaUesiyikjDUNAz5VGD0wuq42C3bgyqtAtbb1FaBkr9ew38IdGtB4MjfJXDFQqB3jAyF3MAoceLXGEf2uMMiNXZa+G8pcmAwW4w6y/ghaDUTuhAi0w04SOO9+aZAjwMN0dQO2y6nb8zRtTOzEW2TAt6RwZAtS9lZ2TaCH5iX0m3RXQV1MRpGFNZOJQ5MudyZXMNlcSA8UFmASjwUdulom5GUrguZK5V9SXbLvii+ZnnaHpBjTzfK7IN16ujpB1E2KUqsM6NJQAY9ydL4ykpvANb6nuywPg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from PAXPR04MB8510.eurprd04.prod.outlook.com (2603:10a6:102:211::7) by VI1PR04MB6847.eurprd04.prod.outlook.com (2603:10a6:803:134::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8048.16; Thu, 10 Oct 2024 09:35:44 +0000 Received: from PAXPR04MB8510.eurprd04.prod.outlook.com ([fe80::a7c2:e2fa:8e04:40db]) by PAXPR04MB8510.eurprd04.prod.outlook.com ([fe80::a7c2:e2fa:8e04:40db%7]) with mapi id 15.20.8026.019; Thu, 10 Oct 2024 09:35:42 +0000 From: Wei Fang To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, claudiu.manoil@nxp.com, vladimir.oltean@nxp.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, stable@vger.kernel.org, imx@lists.linux.dev, rkannoth@marvell.com, maciej.fijalkowski@intel.com, sbhatta@marvell.com Subject: [PATCH v4 net 2/4] net: enetc: block concurrent XDP transmissions during ring reconfiguration Date: Thu, 10 Oct 2024 17:20:54 +0800 Message-Id: <20241010092056.298128-3-wei.fang@nxp.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241010092056.298128-1-wei.fang@nxp.com> References: <20241010092056.298128-1-wei.fang@nxp.com> Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SI2PR01CA0002.apcprd01.prod.exchangelabs.com (2603:1096:4:191::21) To PAXPR04MB8510.eurprd04.prod.outlook.com (2603:10a6:102:211::7) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PAXPR04MB8510:EE_|VI1PR04MB6847:EE_ X-MS-Office365-Filtering-Correlation-Id: 78ad2d32-6bca-49e0-9118-08dce90ee85e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|52116014|366016|7416014|376014|921020|38350700014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?QoSr4o+bxY4l9afy8UanIBQphXuzwnKwxeZRQYp3th3jEGbSBvH+cQlp4+Zl?= =?us-ascii?Q?ecP2u/r14netWJbdELDsg/gZCQs03NzPXi5MsdR4V+d1oSrFfHZ6hrIjQ81+?= =?us-ascii?Q?gEHr4uHV1z1oWFD4w/VtTrnanwIXsmwMC/3XElvb76xRcI4veAoCVrPK4zUG?= =?us-ascii?Q?hZwB25puvDwunuyhlTvQ21hrYmtgugZhBgxZa3mjW+uUV4fcondAZ8L6UvBz?= =?us-ascii?Q?eb4GU/gHZR8eoWtxRSBqpErfpEq6p844ln19q8FV1G623fgDySWX/AwEf6Sd?= =?us-ascii?Q?gKTz/Jyc07h4lTHGn/UA4Pxhu0y4GTbibrMjDY9jzXCpap6w1egsJLbbNm5W?= =?us-ascii?Q?1xc9Xp8FL3B1s+KQVpzzlLlqjS9UWx4T32pDjSs48uRs7cuvcKYQxqDbgHQp?= =?us-ascii?Q?snprOibMKEa3LlEuubpUWbmJXpKEbaTbNrsjhLN5f4WmHuyEKkV2MS+IM1wa?= =?us-ascii?Q?u1fyalmWnOk1EVLZ2AHYjhuHt4bcGJOiSVkia0urjuY7rlwqXr5GzOes5ceO?= =?us-ascii?Q?PqmJ8IaOp3hTBfKuMuViCd63lxwbvzSLBv3KPAYVf/nMFWYww8DaScYSEO1r?= =?us-ascii?Q?Wvd2fJRe1ydaETIsKQ5aOFV9A3GbA4BHkraQZZmmp9cgGy8dcVR8wcRz1MsW?= =?us-ascii?Q?1YHs/2wGhKM8MZJ6mS6TQv+vnSz91cVOaX8SVZv+iTnjTmkf9WlZ0nqE+wjH?= =?us-ascii?Q?Yr4zCmhANCSPQy5Z9JuwFGlVmHlHDyUvBPxnxDkZysEWbv186Mr1MXJu7lAA?= =?us-ascii?Q?DSpCED6ysOwL8dnEBLjzLIxEk+IDrkdWZi2nBfLvqTB69nkB3ygEKy8tSYkQ?= =?us-ascii?Q?QLFwh1LBNUvpNstZL3pvryOm2C30G1dROKkKxL+7Q705H8q9u8ftW7mrZWRB?= =?us-ascii?Q?u/+fHy8fDYB582xGL1F/Ff/3PtySwilqBZL5UVpldXzMGvcz0yXgqLtAiXvq?= =?us-ascii?Q?qG6yaPB7c1ayM9fUsIyzyBeYkOuRcIOg85kQ7sbXF16etns91r8jPx4I/5ck?= =?us-ascii?Q?1H2QyWEoaPDdhp4KNZFFY7ZlCq/lYYRy4uPxUBKrQIf6d1SvbQyHf9IvTf0z?= =?us-ascii?Q?Sc7UBpq9w6AS9TiiCD5Yc0SJ8xLPZ8Jsqy5bGCd5lynDAq3DkZ3U7jOheYo0?= =?us-ascii?Q?+TvzAJYKUWsHVjgrQm0GxfnhiQcbpZTl+2lDIN1Eu8dcr5+zh2rEKEAJGAJ4?= =?us-ascii?Q?lDXBrvVJ2lyqHOo+2eDebckYXog+3dqzAjqSIuZ/U28O9AsuJiksuQHNbIfD?= =?us-ascii?Q?XgBpW/khmZFom0N0d35+gL+UqjEM99pMJ1vyhS9i/8U40LKecYVOUYZZADIW?= =?us-ascii?Q?p1OsdhLOeA4qrogPRBynb7U4MddZcWI6j/PuEzMK1mGEKg=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PAXPR04MB8510.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(52116014)(366016)(7416014)(376014)(921020)(38350700014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?7DBqAHjteWfRL6Ks0D+HDq10o3VQ2mALdAHXLUUrtXOpWm9vnbGFcf5y8yc1?= =?us-ascii?Q?vQtTqToAX2iic6sFhcFrBvfapdzHthXOXMBrkvFsXzZEDj8BoM1HBmzfHd9u?= =?us-ascii?Q?9A9McvMsb7AZaYXI6vi+sYFD9iMKvdAbBuR/Ff/+ZQ4OjUCnnce/PvQ7ojkX?= =?us-ascii?Q?ygwTsmb3+hXZE0/v9rVZ0I9s27I+fkxWYA9PMmVGHh/P3S46eUHqRscXaFfy?= =?us-ascii?Q?9t7auZ1DpSKhXHUYuO5db1W6OQ0gk0+wTSKCtI0dOpLgthTiING26BDO4jBW?= =?us-ascii?Q?8ZvMPtu3wrblvR98koXdX3ZINZ4s7I1lxc8+f5U2OXYQxcx+Sq9kzIOY+tiU?= =?us-ascii?Q?3EzpAd79W7zJ2HLSSZnqheDiIbUBPUZCfJY3qW6J/QJ+kWio2anduiKhSI0y?= =?us-ascii?Q?6XzM9cTOqimazrgFzuGyvFMpAqoTa9fEwSgqPTkixtxeH8AqbvanMi2R/jFX?= =?us-ascii?Q?DZjRSWO+IZiws1KERvGPzZ+T4+OrxJCF62FjwUjQpT0T4PPU+UzXuM5i0IX/?= =?us-ascii?Q?mw0HCUxN1DLvHgkT8QXKxzBDcy+U8hWbqVZ9W22xF/a5bgLX0ltEAnAHdWsX?= =?us-ascii?Q?IDp8h8Q+kPT3AspzJxV0PnZQM9LHsKX8fX8kmpAXlC/Btr/tIhcm9nYVimBT?= =?us-ascii?Q?GLdpsu/QAjNoN2QqbQSGw9a0bbeZ6cgU+xxTef16MEXJQIOY9k87+zD+howQ?= =?us-ascii?Q?EavKjk4CqzwObBiMw4ttwmru+qAHob7VPa4Tk01iqGhQsY/TtZQr0LUV13io?= =?us-ascii?Q?k15Crt6A3ClheJFVEbvpexnxWbqXN1CN0ue3+Fa5Dy1WK7Wgtb5/8NJaQ4bY?= =?us-ascii?Q?poJdXazWbz/5lAZezQjlZA9F6i8dnKTbnGIwaUkpAqVKle48/GPBO2J3G7H1?= =?us-ascii?Q?owgrf6CKlwokNOOiAI92Gr2F2fJfPQHwhn3rO+FTxdMQFd7gPHQ6J05B1VUk?= =?us-ascii?Q?YKIeS4JXsyOX8wwtCF4B/utO4u069U4FqO/h7ePaNrOY3juwaWoFLhHdk5/A?= =?us-ascii?Q?TnGpTVxCpHlB+ui3J2+81KQdbDBT51Ot7dqe7/htGcn1Ywst+IfwIoBurVY1?= =?us-ascii?Q?ldp8/4/WMaJ/kkUUo6cv6sFNWLJPvsJAcNHhwggHac6TjwU/A9BHHNSHtUDo?= =?us-ascii?Q?e9shBTsL+Vpvss5h89wyFlCDGJLe8SnnVlCh7auywNjzA99Zo584eNnv10gu?= =?us-ascii?Q?7/harDeN7juIvB2u6FMWzGyeAhNSjTH0+s2WwdWeI0iw84nC37cRC+/GSdeG?= =?us-ascii?Q?ppb0xDOsvYpBDI1ptzfatx5O/ncAkjKE6Qs9bg6owhJFHZt1RgBJhrlBBMBQ?= =?us-ascii?Q?4coQMoNenrxlZ5TFqSVtoG4hhPSjmbOI5NWOY4jh4Jl1hUwNUe9IgBO6POq1?= =?us-ascii?Q?nQdVXmRRnVkGfDBMBP04Pm32AxJ5syw2eS5pX1WJFnzt4mu5bkx0rwTRoJPn?= =?us-ascii?Q?prbHnFxckE0CA8fIHGX/BjR9emtZTLI4o4mEocVPuX+LKgV6Q/AaUDeRB6P6?= =?us-ascii?Q?7KyXDqilY9p7aiU0IrCQx8KSchnZW8ag+bnGtIPXKoTz1D9TZWyCRu2TefU5?= =?us-ascii?Q?odNLRrTmi8+7RlSNMiOlQyAEQokkxWfKIP+8L+ko?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 78ad2d32-6bca-49e0-9118-08dce90ee85e X-MS-Exchange-CrossTenant-AuthSource: PAXPR04MB8510.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Oct 2024 09:35:41.9756 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: S2GCL8FGF6vVIwr1V2LsIaMaKussCZBdrYlqJL+drMkfdJOChg0do3WEEpdzhYITcMQemyFu/CDYAYq9l2IPmg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB6847 Content-Type: text/plain; charset="utf-8" When testing the XDP_REDIRECT function on the LS1028A platform, we found a very reproducible issue that the Tx frames can no longer be sent out even if XDP_REDIRECT is turned off. Specifically, if there is a lot of traffic on Rx direction, when XDP_REDIRECT is turned on, the console may display some warnings like "timeout for tx ring #6 clear", and all redirected frames will be dropped, the detailed log is as follows. root@ls1028ardb:~# ./xdp-bench redirect eno0 eno2 Redirecting from eno0 (ifindex 3; driver fsl_enetc) to eno2 (ifindex 4; dri= ver fsl_enetc) [203.849809] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #5 clear [204.006051] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #6 clear [204.161944] fsl_enetc 0000:00:00.2 eno2: timeout for tx ring #7 clear eno0->eno2 1420505 rx/s 1420590 err,drop/s 0 xmit/s xmit eno0->eno2 0 xmit/s 1420590 drop/s 0 drv_err/s 15.71 = bulk-avg eno0->eno2 1420484 rx/s 1420485 err,drop/s 0 xmit/s xmit eno0->eno2 0 xmit/s 1420485 drop/s 0 drv_err/s 15.71 = bulk-avg By analyzing the XDP_REDIRECT implementation of enetc driver, the driver will reconfigure Tx and Rx BD rings when a bpf program is installed or uninstalled, but there is no mechanisms to block the redirected frames when enetc driver reconfigures rings. Similarly, XDP_TX verdicts on received frames can also lead to frames being enqueued in the Tx rings. Because XDP ignores the state set by the netif_tx_wake_queue() API, so introduce the ENETC_TX_DOWN flag to suppress transmission of XDP frames. Fixes: c33bfaf91c4c ("net: enetc: set up XDP program under enetc_reconfigur= e()") Cc: stable@vger.kernel.org Signed-off-by: Wei Fang Reviewed-by: Vladimir Oltean --- v2 changes: Remove a blank line from the end of enetc_disable_tx_bdrs(). v3 changes: Block the XDP_TX frames when ENETC_TX_DOWN flag is set. v4 changes: 1. Modify the title and rephrase the commit message. 2. Move the changes of operation order in enect_stop() and enetc_stop() to a separated patch (patch 3). --- drivers/net/ethernet/freescale/enetc/enetc.c | 14 ++++++++++++++ drivers/net/ethernet/freescale/enetc/enetc.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/eth= ernet/freescale/enetc/enetc.c index 56e59721ec7d..482c44ed9d46 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -902,6 +902,7 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ri= ng, int napi_budget) =20 if (unlikely(tx_frm_cnt && netif_carrier_ok(ndev) && __netif_subqueue_stopped(ndev, tx_ring->index) && + !test_bit(ENETC_TX_DOWN, &priv->flags) && (enetc_bd_unused(tx_ring) >=3D ENETC_TXBDS_MAX_NEEDED))) { netif_wake_subqueue(ndev, tx_ring->index); } @@ -1377,6 +1378,9 @@ int enetc_xdp_xmit(struct net_device *ndev, int num_f= rames, int xdp_tx_bd_cnt, i, k; int xdp_tx_frm_cnt =3D 0; =20 + if (unlikely(test_bit(ENETC_TX_DOWN, &priv->flags))) + return -ENETDOWN; + enetc_lock_mdio(); =20 tx_ring =3D priv->xdp_tx_ring[smp_processor_id()]; @@ -1602,6 +1606,12 @@ static int enetc_clean_rx_ring_xdp(struct enetc_bdr = *rx_ring, break; case XDP_TX: tx_ring =3D priv->xdp_tx_ring[rx_ring->index]; + if (unlikely(test_bit(ENETC_TX_DOWN, &priv->flags))) { + enetc_xdp_drop(rx_ring, orig_i, i); + tx_ring->stats.xdp_tx_drops++; + break; + } + xdp_tx_bd_cnt =3D enetc_rx_swbd_to_xdp_tx_swbd(xdp_tx_arr, rx_ring, orig_i, i); @@ -2463,6 +2473,8 @@ void enetc_start(struct net_device *ndev) enetc_enable_bdrs(priv); =20 netif_tx_start_all_queues(ndev); + + clear_bit(ENETC_TX_DOWN, &priv->flags); } EXPORT_SYMBOL_GPL(enetc_start); =20 @@ -2520,6 +2532,8 @@ void enetc_stop(struct net_device *ndev) struct enetc_ndev_priv *priv =3D netdev_priv(ndev); int i; =20 + set_bit(ENETC_TX_DOWN, &priv->flags); + netif_tx_stop_all_queues(ndev); =20 enetc_disable_bdrs(priv); diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/eth= ernet/freescale/enetc/enetc.h index 97524dfa234c..fb7d98d57783 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.h +++ b/drivers/net/ethernet/freescale/enetc/enetc.h @@ -325,6 +325,7 @@ enum enetc_active_offloads { =20 enum enetc_flags_bit { ENETC_TX_ONESTEP_TSTAMP_IN_PROGRESS =3D 0, + ENETC_TX_DOWN, }; =20 /* interrupt coalescing modes */ --=20 2.34.1