From mboxrd@z Thu Jan 1 00:00:00 1970 From: andrew@lunn.ch (Andrew Lunn) Date: Wed, 29 Aug 2018 15:08:36 +0200 Subject: [PATCH 4/5] net: mvneta: enable NETIF_F_RXCSUM by default In-Reply-To: <20180829162932.6015e89d@xhacker.debian> References: <20180829162456.2bd69796@xhacker.debian> <20180829162932.6015e89d@xhacker.debian> Message-ID: <20180829130836.GD1955@lunn.ch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Aug 29, 2018 at 04:29:32PM +0800, Jisheng Zhang wrote: > The code and HW supports NETIF_F_RXCSUM, so let's enable it by default. Hi Jisheng I've never studied what all these different flags mean. Does NETIF_F_RXCSUM mean Ethernet FCS? Or does it also include IPv4, IPv6, UDP, TCP... checksums? I've seen network interfaces get checksum'ing wrong when used with an Ethernet switch with DSA. The extra header DSA uses means the hardware cannot parse the packet correctly, and so cannot find these headers. If this is just for FCS, then it is not a problem. Thanks Andrew 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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 5B73CC433F5 for ; Wed, 29 Aug 2018 13:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F36502084E for ; Wed, 29 Aug 2018 13:08:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="DQakR++1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F36502084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lunn.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728542AbeH2RFb (ORCPT ); Wed, 29 Aug 2018 13:05:31 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:46332 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727537AbeH2RFa (ORCPT ); Wed, 29 Aug 2018 13:05:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=9E0h/7VzFwMRNl9y/NWYbEpER0tO12WyFibW07WCxO8=; b=DQakR++1dMvzELHojo6wBeMBMbpxnVjxGlVcg/7xDw9fPIfRB+V7KeoFznb7tQXntkk+uezVUv01gPpdhBZgvD3EnJCq3yZt9YgdMSt62GEQbWfW4kg8LIuPazX/wnZdU/TTeEZSQzRLxJsw3B08hgLK+GV7S7a/ow+Hn7hv6n4=; Received: from andrew by vps0.lunn.ch with local (Exim 4.84_2) (envelope-from ) id 1fv0D6-0000pH-2G; Wed, 29 Aug 2018 15:08:36 +0200 Date: Wed, 29 Aug 2018 15:08:36 +0200 From: Andrew Lunn To: Jisheng Zhang Cc: thomas.petazzoni@bootlin.com, "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Gregory CLEMENT , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 4/5] net: mvneta: enable NETIF_F_RXCSUM by default Message-ID: <20180829130836.GD1955@lunn.ch> References: <20180829162456.2bd69796@xhacker.debian> <20180829162932.6015e89d@xhacker.debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180829162932.6015e89d@xhacker.debian> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 29, 2018 at 04:29:32PM +0800, Jisheng Zhang wrote: > The code and HW supports NETIF_F_RXCSUM, so let's enable it by default. Hi Jisheng I've never studied what all these different flags mean. Does NETIF_F_RXCSUM mean Ethernet FCS? Or does it also include IPv4, IPv6, UDP, TCP... checksums? I've seen network interfaces get checksum'ing wrong when used with an Ethernet switch with DSA. The extra header DSA uses means the hardware cannot parse the packet correctly, and so cannot find these headers. If this is just for FCS, then it is not a problem. Thanks Andrew