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 X-Spam-Level: X-Spam-Status: No, score=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 395EDC433ED for ; Sat, 8 May 2021 20:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DD1961106 for ; Sat, 8 May 2021 20:47:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229559AbhEHUsx (ORCPT ); Sat, 8 May 2021 16:48:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229522AbhEHUsv (ORCPT ); Sat, 8 May 2021 16:48:51 -0400 Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6FECC061574; Sat, 8 May 2021 13:47:43 -0700 (PDT) Received: by mail-lj1-x233.google.com with SMTP id p12so15991264ljg.1; Sat, 08 May 2021 13:47:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ZqFjcJzwpOTq9GtmlmbZMzkDp6Su/3i4cPc+0PSnWlU=; b=cmUr1lOfJQc0OQ/TSE6xJZKM6LHx0PUpIU8QmhASSx1zAOnkbpdOCgQiW9iwyK6Mrs UzxXZVPtdhXnrYifjJuslr98k4/wmGHgK+OtCJRbgHYZrzPu1IitgQREtO3YSPVZK44W /g5+BNelIICkFpisnLctaQqW4nO3MeG8OcY9B8AbGFDf2ifqoks1+cuLThbU146+XlMr daRqIGaFckxMr2xnF3ChWSAY5bLNW5eb1MsXO1VJ555wZsqiBc82qPizeRPhdysMndjO tPnOmGP+vzMtngj7kq5zNTOWVYgHgjoFqcnEGmpMbezzvMuU9r89bYUIc3rvgM2LO97K g7qw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ZqFjcJzwpOTq9GtmlmbZMzkDp6Su/3i4cPc+0PSnWlU=; b=r3z0zwyeCMpIkN5pEkoRfizHDAfPG9DeQY5seXLME6uyV9vTcOvZiYjxLkLPfCU+Qi KNGJbrA9MNlfcU0HmQ2c+2JBnXlDX+7l4sHSr8rTaqYnGAxBIy6jSWbPTYr6YQxEAbI8 jUjaM+FAck+oznl0pugbZfii71d+Sw7MwRclBJgbmGBNGCpyegnXsjSiUtKeyOzvpUR+ NByz32UVZOR5XZelpaspYVT4sPVfey1DGRL9t5fFBx07F6pJxI63PMGin8zlsmbAGvYd cRHZDW3iK9GtTdAf4290EQmNlbrM3ZWlReJvb+z4AxecVcdIgI9FC5LX4oGoBrj2TCXQ Fkig== X-Gm-Message-State: AOAM531wd3oFdES9Ztfp6t7g9daERqff9461CkC82SpFsZWhx3qhfP/G i86kG6PaZgX35l8ta1Q0o/zZ7YBh/jc= X-Google-Smtp-Source: ABdhPJyiz1w+vQYC5qSHYCxHJXVe/+ciNhxyTz6jlOHgcQ2N1d7ee4a9piwACRFnLDoOJJwasqHYYw== X-Received: by 2002:a2e:a309:: with SMTP id l9mr10405525lje.132.1620506862079; Sat, 08 May 2021 13:47:42 -0700 (PDT) Received: from [192.168.1.102] ([31.173.86.161]) by smtp.gmail.com with ESMTPSA id h18sm612371ljm.27.2021.05.08.13.47.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 08 May 2021 13:47:41 -0700 (PDT) Subject: Re: [PATCH] net: renesas: ravb: Fix a stuck issue when a lot of frames are received To: Yoshihiro Shimoda , davem@davemloft.net, kuba@kernel.org Cc: netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org References: <20210421045246.215779-1-yoshihiro.shimoda.uh@renesas.com> From: Sergei Shtylyov Message-ID: <68291557-0af5-de1e-4f4f-b104bb65c6b3@gmail.com> Date: Sat, 8 May 2021 23:47:40 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210421045246.215779-1-yoshihiro.shimoda.uh@renesas.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello! On 4/21/21 7:52 AM, Yoshihiro Shimoda wrote: Posting a review of the already commited (over my head) patch. It would have been appropriate if the patch looked OK but it's not. :-/ > When a lot of frames were received in the short term, the driver > caused a stuck of receiving until a new frame was received. For example, > the following command from other device could cause this issue. > > $ sudo ping -f -l 1000 -c 1000 -l is essential here, right? Have you tried testing sh_eth sriver like that, BTW? > The previous code always cleared the interrupt flag of RX but checks > the interrupt flags in ravb_poll(). So, ravb_poll() could not call > ravb_rx() in the next time until a new RX frame was received if > ravb_rx() returned true. To fix the issue, always calls ravb_rx() > regardless the interrupt flags condition. That bacially defeats the purpose of IIUC... > Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") > Signed-off-by: Yoshihiro Shimoda > --- > drivers/net/ethernet/renesas/ravb_main.c | 35 ++++++++---------------- > 1 file changed, 12 insertions(+), 23 deletions(-) > > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c > index eb0c03bdb12d..cad57d58d764 100644 > --- a/drivers/net/ethernet/renesas/ravb_main.c > +++ b/drivers/net/ethernet/renesas/ravb_main.c > @@ -911,31 +911,20 @@ static int ravb_poll(struct napi_struct *napi, int budget) > int q = napi - priv->napi; > int mask = BIT(q); > int quota = budget; > - u32 ris0, tis; > > - for (;;) { > - tis = ravb_read(ndev, TIS); > - ris0 = ravb_read(ndev, RIS0); > - if (!((ris0 & mask) || (tis & mask))) > - break; > + /* Processing RX Descriptor Ring */ > + /* Clear RX interrupt */ I think these 2 coments should've been collapsed... > + ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0); > + if (ravb_rx(ndev, "a, q)) > + goto out; > > - /* Processing RX Descriptor Ring */ > - if (ris0 & mask) { > - /* Clear RX interrupt */ > - ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0); > - if (ravb_rx(ndev, "a, q)) > - goto out; This jumps over the TX NAPI code, not good... Seems like another bug. > - } > - /* Processing TX Descriptor Ring */ > - if (tis & mask) { > - spin_lock_irqsave(&priv->lock, flags); > - /* Clear TX interrupt */ > - ravb_write(ndev, ~(mask | TIS_RESERVED), TIS); > - ravb_tx_free(ndev, q, true); > - netif_wake_subqueue(ndev, q); > - spin_unlock_irqrestore(&priv->lock, flags); > - } > - } > + /* Processing RX Descriptor Ring */ TX! > + spin_lock_irqsave(&priv->lock, flags); > + /* Clear TX interrupt */ > + ravb_write(ndev, ~(mask | TIS_RESERVED), TIS); > + ravb_tx_free(ndev, q, true); > + netif_wake_subqueue(ndev, q); > + spin_unlock_irqrestore(&priv->lock, flags); > > napi_complete(napi); > MBR, Sergei