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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham 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 C7973C433DB for ; Thu, 4 Feb 2021 19:18:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7958B64F10 for ; Thu, 4 Feb 2021 19:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239763AbhBDTSR (ORCPT ); Thu, 4 Feb 2021 14:18:17 -0500 Received: from mga03.intel.com ([134.134.136.65]:60733 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239741AbhBDTR4 (ORCPT ); Thu, 4 Feb 2021 14:17:56 -0500 IronPort-SDR: Nq5cIV1IS1h0RKXRFYh/5yoSwDXzphIrBvbFtoFJS2guw0fHuTuWOL6FiJ3CEpJy45BAbNfBMd SrJvTR1t8mVg== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="181378958" X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="181378958" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 11:17:14 -0800 IronPort-SDR: +Dhe4crGnrdhv7EDuKjorK7XTvF6epnPsutQfLmU4tiTiuUxJOVHxqgqjJTpoeH7McB2x8YApT W26CcC5hJUmg== X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="393331149" Received: from jbrandeb-mobl4.amr.corp.intel.com (HELO localhost) ([10.212.188.246]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 11:17:14 -0800 Date: Thu, 4 Feb 2021 11:17:13 -0800 From: Jesse Brandeburg To: Loic Poulain Cc: kuba@kernel.org, davem@davemloft.net, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, stranche@codeaurora.org, subashab@codeaurora.org Subject: Re: [PATCH net-next v5 1/2] net: mhi-net: Add re-aggregation of fragmented packets Message-ID: <20210204111713.00005fb6@intel.com> In-Reply-To: <1612428002-12333-1-git-send-email-loic.poulain@linaro.org> References: <1612428002-12333-1-git-send-email-loic.poulain@linaro.org> X-Mailer: Claws Mail 3.12.0 (GTK+ 2.24.28; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Loic Poulain wrote: > When device side MTU is larger than host side MTU, the packets > (typically rmnet packets) are split over multiple MHI transfers. > In that case, fragments must be re-aggregated to recover the packet > before forwarding to upper layer. > > A fragmented packet result in -EOVERFLOW MHI transaction status for > each of its fragments, except the final one. Such transfer was > previously considered as error and fragments were simply dropped. > > This change adds re-aggregation mechanism using skb chaining, via > skb frag_list. > > A warning (once) is printed since this behavior usually comes from > a misconfiguration of the device (e.g. modem MTU). > > Signed-off-by: Loic Poulain > --- > v2: use zero-copy skb chaining instead of skb_copy_expand. > v3: Fix nit in commit msg + remove misleading inline comment for frag_list > v4: no change > v5: reword/fix commit subject > Acked-by: Jesse Brandeburg