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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 3AD16C3A5A1 for ; Thu, 29 Aug 2019 00:30:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C94622CF8 for ; Thu, 29 Aug 2019 00:30:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="NkGuqix2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727020AbfH2AaA (ORCPT ); Wed, 28 Aug 2019 20:30:00 -0400 Received: from mail-ed1-f67.google.com ([209.85.208.67]:41461 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbfH2A37 (ORCPT ); Wed, 28 Aug 2019 20:29:59 -0400 Received: by mail-ed1-f67.google.com with SMTP id w5so1978959edl.8 for ; Wed, 28 Aug 2019 17:29:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=ABqqYv/EJP79rddAp3kaLn+kdqDhIPG0VmK8KQ/CWko=; b=NkGuqix2BUGQi0p44g6C6u3I6X6lMJTFG1zGDZvKJOBkTVGGlTelT0rTC1rt5U1Kih 6uBO1kMYn7XyXfqoqdZLiwB82hFnEfPHOiSNIs1ve2T0pEJwpNC+2UIQfu70+U50FZia 9v0w79wSKED1VzkIB2BkYjEM6K8j7w7YE2d6KhBBgQZP+3oaYH/zubvi+9zXmQlwKWaI 7pqxTaWH6SDN+8v0oB7dQwtHnwsm+jD/Fp5TlzS6ohJycsOygpOsOvIZfBoHxJEiZDUr pR7IgIn5CTcXShXQK+VkydMsqhqGOCz/eJ1sYo0chf8F0cl69hLRbBYSEyYZtLqyClvy F0pQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=ABqqYv/EJP79rddAp3kaLn+kdqDhIPG0VmK8KQ/CWko=; b=eW7JPCxHMmEXE5iHiDH9n1oqbVLlzqB70wcVT2wewunKhuVGuIbpr6Zg6uuB3Mmc8C uyCMNrcSXRJV4HW/SA1hS4mre72abnZv2vb/kdoKrVC9ZrEqAXXHKSzgo8t1KVZYb3cu LEa4Hxw0I6MrIiAVl5ZeoNoigP+Xi8lL9VAJyC8OFmYiPPIedeNlyj2ZRWK5nMimsOaL OpMzIDlTk3JooRRBz9OkrZN+WvcBGjYL2oJlHvtaI2ji6UmCqwaQzggCxc3glEPmdYKg O9VEboPDlNlotDBwEEej4Fvbr1/4VDNEz7kMo7AtV9DIILMpbCZrd8WXgKiYCZEggsgY SdxA== X-Gm-Message-State: APjAAAW2v/hIWMa43/NWfTvtvzLXIVmQXFRVwWFmOYxRLxbVv2NoLf9m 7YYGBks2L/sTxuq58E4PHDSI2Q== X-Google-Smtp-Source: APXvYqz/mLlvZgSx6ApWhudr8RXP/HK39miTKk+n1hE/evZerYM619Sq9w6sz9FcNk74+m+jJ3fr/Q== X-Received: by 2002:a17:907:207a:: with SMTP id qp26mr5718366ejb.12.1567038598027; Wed, 28 Aug 2019 17:29:58 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id s8sm126520edq.79.2019.08.28.17.29.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Aug 2019 17:29:57 -0700 (PDT) Date: Wed, 28 Aug 2019 17:29:34 -0700 From: Jakub Kicinski To: Heiner Kallweit Cc: Realtek linux nic maintainers , David Miller , "netdev@vger.kernel.org" , Chun-Hao Lin Subject: Re: [PATCH net-next v2 6/9] r8169: don't use bit LastFrag in tx descriptor after send Message-ID: <20190828172934.57a2a169@cakuba.netronome.com> In-Reply-To: <5b4c94bf-4571-7b36-1d83-c169980a6867@gmail.com> References: <8181244b-24ac-73e2-bac7-d01f644ebb3f@gmail.com> <5b4c94bf-4571-7b36-1d83-c169980a6867@gmail.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 28 Aug 2019 22:27:30 +0200, Heiner Kallweit wrote: > On RTL8125 this bit is always cleared after send. Therefore check for > tx_skb->skb being set what is functionally equivalent. > > Signed-off-by: Heiner Kallweit > --- > drivers/net/ethernet/realtek/r8169_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c > index 652bacf62..4489cd9f2 100644 > --- a/drivers/net/ethernet/realtek/r8169_main.c > +++ b/drivers/net/ethernet/realtek/r8169_main.c > @@ -5713,7 +5713,7 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, > > rtl8169_unmap_tx_skb(tp_to_dev(tp), tx_skb, > tp->TxDescArray + entry); > - if (status & LastFrag) { > + if (tx_skb->skb) { > pkts_compl++; > bytes_compl += tx_skb->skb->len; > napi_consume_skb(tx_skb->skb, budget); Hmm.. the dma_rmb() looks a little sus. Honestly I'm unclear on what it was doing in the first place. READ_ONCE() should've been sufficient.. And it's not obviously clear what does the smp_rmb() at the start of the function pair with. But I don't think you're making anything worse here :)