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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 9C66BC43381 for ; Mon, 4 Mar 2019 05:15:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 758622082F for ; Mon, 4 Mar 2019 05:15:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726047AbfCDFPU (ORCPT ); Mon, 4 Mar 2019 00:15:20 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:57014 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725550AbfCDFPT (ORCPT ); Mon, 4 Mar 2019 00:15:19 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id B2BA514D42E33; Sun, 3 Mar 2019 21:15:18 -0800 (PST) Date: Sun, 03 Mar 2019 21:15:18 -0800 (PST) Message-Id: <20190303.211518.1265133811120263144.davem@davemloft.net> To: tanhuazhong@huawei.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, salil.mehta@huawei.com, yisen.zhuang@huawei.com, linuxarm@huawei.com, shenjian15@huawei.com Subject: Re: [PATCH net] net: hns3: add rmb() for rx description From: David Miller In-Reply-To: <1551516570-1067-1-git-send-email-tanhuazhong@huawei.com> References: <1551516570-1067-1-git-send-email-tanhuazhong@huawei.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sun, 03 Mar 2019 21:15:19 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huazhong Tan Date: Sat, 2 Mar 2019 16:49:30 +0800 > From: Jian Shen > > HW can not guarantee complete write desc->rx.size, even though > HNS3_RXD_VLD_B has been set. Driver needs to add rmb() instruction > to make sure desc->rx.size is always valid. > > Fixes: e55970950556 ("net: hns3: Add handling of GRO Pkts not fully RX'ed in NAPI poll") > Signed-off-by: Jian Shen > Signed-off-by: Huazhong Tan dma_rmb() is more appropriate here and more efficient.