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 1CB41C4332F for ; Mon, 12 Dec 2022 13:29:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232279AbiLLN3x (ORCPT ); Mon, 12 Dec 2022 08:29:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232273AbiLLN3u (ORCPT ); Mon, 12 Dec 2022 08:29:50 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D52DDE for ; Mon, 12 Dec 2022 05:29:49 -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 CEFC8B80D50 for ; Mon, 12 Dec 2022 13:29:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2F99C433F1; Mon, 12 Dec 2022 13:29:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670851786; bh=K4h1LllvwlNc1f/xDUX88nq0rFIad23DyAbdzb2zCdE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gBejRDVXHSSPHpkQp+k1uqgz9OFQcs4S4Mb2wqFv0tvM749wWgJOi5cEJ0D250cwj Xw/4adK85cp8l1SOhiqf4Gg1uSI2BjK0YImit4OwrMkVPBIpc6UXD8KvEc62AsXTFG 05JAWaEtP01d93a2r+ZvzAPUhawBjCttPtdsN8M4= 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 5.15 070/123] e1000e: Fix TX dispatch condition Date: Mon, 12 Dec 2022 14:17:16 +0100 Message-Id: <20221212130929.902664786@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221212130926.811961601@linuxfoundation.org> References: <20221212130926.811961601@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 407bbb4cc236..7e41ce188cc6 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5941,9 +5941,9 @@ 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