From patchwork Tue Oct 20 22:06:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Stanley X-Patchwork-Id: 288245 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07299C4363D for ; Tue, 20 Oct 2020 22:06:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9054322256 for ; Tue, 20 Oct 2020 22:06:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ERepXBwF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410346AbgJTWGx (ORCPT ); Tue, 20 Oct 2020 18:06:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2410338AbgJTWGx (ORCPT ); Tue, 20 Oct 2020 18:06:53 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A4CAC0613CE; Tue, 20 Oct 2020 15:06:53 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id h2so101032pll.11; Tue, 20 Oct 2020 15:06:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=cVxbxuo00dZr6eR4Osdpd7pA7uQ5RC3VinQNVSJSDBU=; b=ERepXBwFXbhB76YhVH5xGuKd028JuTI6ynKg8XjzS4fObj0izAJWcCiDPriiC8pXku K+DeUlNlvy3F4ROWV/ISgHIAxzZANhPIz7OZIgp5Oq599ZnSI44ONUu2w5W/VeXo35OQ uUBuMuDk+99/NP1/cBCCtKIq7MWDHjefGk+tjk+ov6uHWmsvAUAos9GV7lHk8MgiOyGw ml4WzcB1v+xNkvHPCTDCmSQHM8o0qIDIR/nHKwzFDQQ4AI95beVsDc9eHwIG5ahaI4sj UnAtsOrwO1tfY2GnzLy+aR3XZQWbkK8lfGWS5z1rKc3p9/b0r3tutFYYHaU2PqxU6fHO IjPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=cVxbxuo00dZr6eR4Osdpd7pA7uQ5RC3VinQNVSJSDBU=; b=Fp0Ex7F6iLX/8fqIpyr3D6SyzsSVFmDfSzLTfS+HTxt7ycIx04satxnPDExDa16gXN HZJa0GgK119mKFgsKSpXnrlzMSQ2eFDcTo9rXIlhWKKfpj1Tl2HhVZAfLAVrE9NAhFXV HAaZrTQaLe3+uY2A566yR7D82vz3xLEl7Yxa5buEpR4Dm1xzak1scnowmJo3JU7S7LyV nqqLSif2xJYWoZ23LHsPNrqWl3hqojwcPpkJC26eF1wvc8sNRKHUizwG73th8KyDGuvX V/EQk00OrhjN4Yh22DuVKivt5sin0En/DFGpzSjlZob7tZ90ocikmAjHbehhWpsJ/KwN OW0g== X-Gm-Message-State: AOAM533v1jy1WFfsSnmo1mrP/toXZjj0b6dI7Da9GWj3RZxWrHB/LHMh J/BOyNPHQHgH0/oGBUur8H8= X-Google-Smtp-Source: ABdhPJypfdOKEQQS14sOZlqq2wpr5US5/1nAoMDWDZRTMOy6PhaWvsSSH5MIeLOWLLSSdW6Ieb8tCw== X-Received: by 2002:a17:90a:4684:: with SMTP id z4mr179932pjf.97.1603231612719; Tue, 20 Oct 2020 15:06:52 -0700 (PDT) Received: from localhost.localdomain ([45.124.203.15]) by smtp.gmail.com with ESMTPSA id n16sm39974pfo.150.2020.10.20.15.06.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2020 15:06:51 -0700 (PDT) Sender: "joel.stan@gmail.com" From: Joel Stanley To: Jakub Kicinski , "David S . Miller" , Benjamin Herrenschmidt , Dylan Hung Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-aspeed@lists.ozlabs.org Subject: [PATCH] net: ftgmac100: Ensure tx descriptor updates are visible Date: Wed, 21 Oct 2020 08:36:39 +1030 Message-Id: <20201020220639.130696-1-joel@jms.id.au> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We must ensure the tx descriptor updates are visible before updating the tx pointer. This resolves the tx hangs observed on the 2600 when running iperf: root@ast2600:~# iperf3 -c 192.168.86.146 -R Connecting to host 192.168.86.146, port 5201 Reverse mode, remote host 192.168.86.146 is sending [ 5] local 192.168.86.173 port 43886 connected to 192.168.86.146 port 5201 [ ID] Interval Transfer Bitrate [ 5] 0.00-1.00 sec 90.7 MBytes 760 Mbits/sec [ 5] 1.00-2.00 sec 91.7 MBytes 769 Mbits/sec [ 5] 2.00-3.00 sec 91.7 MBytes 770 Mbits/sec [ 5] 3.00-4.00 sec 91.7 MBytes 769 Mbits/sec [ 5] 4.00-5.00 sec 91.8 MBytes 771 Mbits/sec [ 5] 5.00-6.00 sec 91.8 MBytes 771 Mbits/sec [ 5] 6.00-7.00 sec 91.9 MBytes 771 Mbits/sec [ 5] 7.00-8.00 sec 91.4 MBytes 767 Mbits/sec [ 5] 8.00-9.00 sec 91.3 MBytes 766 Mbits/sec [ 5] 9.00-10.00 sec 91.9 MBytes 771 Mbits/sec [ 5] 10.00-11.00 sec 91.8 MBytes 770 Mbits/sec [ 5] 11.00-12.00 sec 91.8 MBytes 770 Mbits/sec [ 5] 12.00-13.00 sec 90.6 MBytes 761 Mbits/sec [ 5] 13.00-14.00 sec 45.2 KBytes 370 Kbits/sec [ 5] 14.00-15.00 sec 0.00 Bytes 0.00 bits/sec [ 5] 15.00-16.00 sec 0.00 Bytes 0.00 bits/sec [ 5] 16.00-17.00 sec 0.00 Bytes 0.00 bits/sec [ 5] 17.00-18.00 sec 0.00 Bytes 0.00 bits/sec [ 67.031671] ------------[ cut here ]------------ [ 67.036870] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:442 dev_watchdog+0x2dc/0x300 [ 67.046123] NETDEV WATCHDOG: eth2 (ftgmac100): transmit queue 0 timed out Fixes: 52c0cae87465 ("ftgmac100: Remove tx descriptor accessors") Signed-off-by: Joel Stanley --- drivers/net/ethernet/faraday/ftgmac100.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c index 331d4bdd4a67..15cdfeb135b0 100644 --- a/drivers/net/ethernet/faraday/ftgmac100.c +++ b/drivers/net/ethernet/faraday/ftgmac100.c @@ -653,6 +653,11 @@ static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv) ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat); txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask); + /* Ensure the descriptor config is visible before setting the tx + * pointer. + */ + smp_wmb(); + priv->tx_clean_pointer = ftgmac100_next_tx_pointer(priv, pointer); return true; @@ -806,6 +811,11 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb, dma_wmb(); first->txdes0 = cpu_to_le32(f_ctl_stat); + /* Ensure the descriptor config is visible before setting the tx + * pointer. + */ + smp_wmb(); + /* Update next TX pointer */ priv->tx_pointer = pointer;