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=-6.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 1B640C433E7 for ; Thu, 15 Oct 2020 12:41:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0EF522258 for ; Thu, 15 Oct 2020 12:41:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OYS0WY2V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727200AbgJOMlr (ORCPT ); Thu, 15 Oct 2020 08:41:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726103AbgJOMlr (ORCPT ); Thu, 15 Oct 2020 08:41:47 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36E70C061755 for ; Thu, 15 Oct 2020 05:41:47 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id g12so3259616wrp.10 for ; Thu, 15 Oct 2020 05:41:47 -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=gVOZeFI6XYUPK4xQnWsbEsH9LP3cSlbrYfYrvw/6j4Y=; b=OYS0WY2VI5/PCZdQ0dMKzBmpX02byLz9sHnng61JzJ2Ypw/oASydU1RyswCqcy1+ST MAaQRFuZ0O6yuteZrUytQSOlDWqmMoZfRXVjwF5a4CwWX6iHjGtzzkYZ4EeUPjn6z41Z k8uHg7TZ0l2XLrrG1ba2b3xAZGmVaW8OXMk2S2FTPIJx/Qu2X+WGrXsx4cywHRzSeDtG IM2nPs7i20fbH3jT6DwjpAiisjabkBBnJiUh2pWpCWugcSq8hh0ePdJByF1k3hHHTqK7 FVN2I6WGx56HUDSSRTXHxPSbXdquFYMUSBJ3dVoqA+vMrp7Cj0qMqffeDt3BqTCtcpZY svKg== 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=gVOZeFI6XYUPK4xQnWsbEsH9LP3cSlbrYfYrvw/6j4Y=; b=qpa653VeIu3HwOZYj0RyE0dhjX0Zb7m5AecI3lhK8gnvbKE0g3642hPfndvbNWARKU kP+h/hH0uK2ryqHRE2gz/COqfHWfauD0OVCA3rw92YqdqYJGkAFK6ba8H5mMpOs/66n2 OxGRvDZdi5x4yQU1HlBrO6p+ofR2c2wqXHQ013IUlrCpUqHx9p1jnPeelfbnwOppwZzW 3sy+rdJ1T2cpz+nvRAGC0s8tB1vrrm6twQtLTdtr6PQB8zBsjXj0a2AuftmmOEy74F+q Be4xi1IzqCYYYOl6vWVklV2rr0CcCuKNG300znHfetQSZTOlM8ftmGNrgYIR6o8lvnj0 +nWw== X-Gm-Message-State: AOAM532+8GKxNKQxpgzQ9BJMcEMpyAuEdopOEUsmwSvZCLTVHZxDlayE O+NPnhUecS/srW0KDbQnfh4= X-Google-Smtp-Source: ABdhPJwrenbBXeHTsjn4r32CQHwKN9rZIMyZKVQxLfB5uGfqIZdXK7B5Au8PgOaZMq7RE5aOuE3fEA== X-Received: by 2002:a5d:4103:: with SMTP id l3mr4180012wrp.260.1602765705958; Thu, 15 Oct 2020 05:41:45 -0700 (PDT) Received: from [192.168.8.147] ([37.165.69.53]) by smtp.gmail.com with ESMTPSA id d3sm2718742wrb.66.2020.10.15.05.41.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 15 Oct 2020 05:41:45 -0700 (PDT) Subject: Re: [PATCH v4 1/2] net: Add mhi-net driver To: Loic Poulain , davem@davemloft.net, kuba@kernel.org Cc: netdev@vger.kernel.org, hemantk@codeaurora.org, manivannan.sadhasivam@linaro.org, eric.dumazet@gmail.com References: <1602757888-3507-1-git-send-email-loic.poulain@linaro.org> From: Eric Dumazet Message-ID: Date: Thu, 15 Oct 2020 14:41:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1602757888-3507-1-git-send-email-loic.poulain@linaro.org> 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 On 10/15/20 12:31 PM, Loic Poulain wrote: > This patch adds a new network driver implementing MHI transport for > network packets. Packets can be in any format, though QMAP (rmnet) > is the usual protocol (flow control + PDN mux). > > It support two MHI devices, IP_HW0 which is, the path to the IPA > (IP accelerator) on qcom modem, And IP_SW0 which is the software > driven IP path (to modem CPU). > > > +static int mhi_ndo_xmit(struct sk_buff *skb, struct net_device *ndev) > +{ > + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); > + struct mhi_device *mdev = mhi_netdev->mdev; > + int err; > + > + skb_tx_timestamp(skb); > + > + /* mhi_queue_skb is not thread-safe, but xmit is serialized by the > + * network core. Once MHI core will be thread save, migrate to > + * NETIF_F_LLTX support. > + */ > + err = mhi_queue_skb(mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT); > + if (err == -ENOMEM) { > + netif_stop_queue(ndev); If you return NETDEV_TX_BUSY, this means this skb will be requeues, then sent again right away, and this will potentially loop forever. Also skb_tx_timestamp() would be called multiple times. I suggest you drop the packet instead. > + return NETDEV_TX_BUSY; > + } else if (unlikely(err)) { > + net_err_ratelimited("%s: Failed to queue TX buf (%d)\n", > + ndev->name, err); > + mhi_netdev->stats.tx_dropped++; > + kfree_skb(skb); > + } > + > + return NETDEV_TX_OK; > +} > + > +static void mhi_ndo_get_stats64(struct net_device *ndev, > + struct rtnl_link_stats64 *stats) > +{ > + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); > + > + stats->rx_packets = mhi_netdev->stats.rx_packets; > + stats->rx_bytes = mhi_netdev->stats.rx_bytes; > + stats->rx_errors = mhi_netdev->stats.rx_errors; > + stats->rx_dropped = mhi_netdev->stats.rx_dropped; > + stats->tx_packets = mhi_netdev->stats.tx_packets; > + stats->tx_bytes = mhi_netdev->stats.tx_bytes; > + stats->tx_errors = mhi_netdev->stats.tx_errors; > + stats->tx_dropped = mhi_netdev->stats.tx_dropped; > +} This code is not correct on a 32bit kernel, since u64 values can not be safely be read without extra care.