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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28395C4708E for ; Mon, 12 Dec 2022 13:16:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232033AbiLLNQY (ORCPT ); Mon, 12 Dec 2022 08:16:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232528AbiLLNQB (ORCPT ); Mon, 12 Dec 2022 08:16:01 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3462D13CC6 for ; Mon, 12 Dec 2022 05:15:48 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E4BA0B80B78 for ; Mon, 12 Dec 2022 13:15:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A2EEC433EF; Mon, 12 Dec 2022 13:15:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670850945; bh=7XtRTI5GgqHR9nSEuGib+YoJslHYD0qH6h6Xk2SMcj4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tAPSz58gyRHuGr/PyVl9OI9JebvTWB4Dpdz1LC5fVNfHShFNtFT3bc5a/4xJceg+w dxupfgDsaACIG/L5e0808O+s6PSXF0Tdwuku0t9jptEVM2EZYWrL0qFjyCLtdw+68/ A4HOc5uEqWXSn9sidQifJ/95P5ss+sWq0eqL5XXM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Akihiko Odaki , Naama Meir , Tony Nguyen , Sasha Levin , Gurucharan G Subject: [PATCH 5.10 070/106] e1000e: Fix TX dispatch condition Date: Mon, 12 Dec 2022 14:10:13 +0100 Message-Id: <20221212130927.937372801@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221212130924.863767275@linuxfoundation.org> References: <20221212130924.863767275@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Akihiko Odaki [ Upstream commit eed913f6919e253f35d454b2f115f2a4db2b741a ] e1000_xmit_frame is expected to stop the queue and dispatch frames to hardware if there is not sufficient space for the next frame in the buffer, but sometimes it failed to do so because the estimated maximum size of frame was wrong. As the consequence, the later invocation of e1000_xmit_frame failed with NETDEV_TX_BUSY, and the frame in the buffer remained forever, resulting in a watchdog failure. This change fixes the estimated size by making it match with the condition for NETDEV_TX_BUSY. Apparently, the old estimation failed to account for the following lines which determines the space requirement for not causing NETDEV_TX_BUSY: ``` /* reserve a descriptor for the offload context */ if ((mss) || (skb->ip_summed == CHECKSUM_PARTIAL)) count++; count++; count += DIV_ROUND_UP(len, adapter->tx_fifo_limit); ``` This issue was found when running http-stress02 test included in Linux Test Project 20220930 on QEMU with the following commandline: ``` qemu-system-x86_64 -M q35,accel=kvm -m 8G -smp 8 -drive if=virtio,format=raw,file=root.img,file.locking=on -device e1000e,netdev=netdev -netdev tap,script=ifup,downscript=no,id=netdev ``` Fixes: bc7f75fa9788 ("[E1000E]: New pci-express e1000 driver (currently for ICH9 devices only)") Signed-off-by: Akihiko Odaki Tested-by: Gurucharan G (A Contingent worker at Intel) Tested-by: Naama Meir Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/e1000e/netdev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index d0c4de023112..ae0c9aaab48d 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5937,9 +5937,9 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb, e1000_tx_queue(tx_ring, tx_flags, count); /* Make sure there is space in the ring for the next send. */ e1000_maybe_stop_tx(tx_ring, - (MAX_SKB_FRAGS * + ((MAX_SKB_FRAGS + 1) * DIV_ROUND_UP(PAGE_SIZE, - adapter->tx_fifo_limit) + 2)); + adapter->tx_fifo_limit) + 4)); if (!netdev_xmit_more() || netif_xmit_stopped(netdev_get_tx_queue(netdev, 0))) { -- 2.35.1