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=-8.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 A8D4EC43461 for ; Thu, 3 Sep 2020 08:47:42 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 282C320767 for ; Thu, 3 Sep 2020 08:47:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="bGAyvAD0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 282C320767 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 9605018C9; Thu, 3 Sep 2020 10:46:49 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 9605018C9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1599122859; bh=03EnqcyQFypnHdghhtGo93qPIb2kvhxNe6h166rB1KQ=; h=Date:From:To:Subject:References:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=bGAyvAD0Y4BabYlp4219troKLDl/F0q1serxfTaCvFFTLU57CBEAElRgSDxP1Zv2o 1Srf3eO8FClALBLLxo1n3Jut/0DC/lXadkmtrBGRse5/mKcEsg7Mnuz0rd7ZMyiVr5 hbqzHa0v+3tE2tJZ1F+98fyqB4SvcuHKao2hUV8Q= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 340C7F8020D; Thu, 3 Sep 2020 10:46:49 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id C501DF80217; Thu, 3 Sep 2020 10:46:47 +0200 (CEST) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 52D00F801DA for ; Thu, 3 Sep 2020 10:46:45 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 52D00F801DA Received: by verein.lst.de (Postfix, from userid 2407) id F0C1868CEE; Thu, 3 Sep 2020 10:46:43 +0200 (CEST) Date: Thu, 3 Sep 2020 10:46:43 +0200 From: Christoph Hellwig To: Thomas Bogendoerfer Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, iommu@lists.linux-foundation.org, Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-kernel@vger.kernel.org, Kyungmin Park X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); 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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 2382EC43461 for ; Thu, 3 Sep 2020 08:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECB3720767 for ; Thu, 3 Sep 2020 08:47:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728107AbgICIqt (ORCPT ); Thu, 3 Sep 2020 04:46:49 -0400 Received: from verein.lst.de ([213.95.11.211]:37058 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726493AbgICIqt (ORCPT ); Thu, 3 Sep 2020 04:46:49 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id F0C1868CEE; Thu, 3 Sep 2020 10:46:43 +0200 (CEST) Date: Thu, 3 Sep 2020 10:46:43 +0200 From: Christoph Hellwig To: Thomas Bogendoerfer Cc: Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-mips@vger.kernel.org, iommu@lists.linux-foundation.org Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Thu, 03 Sep 2020 08:46:43 +0000 Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-Id: <20200903084643.GA25111@lst.de> List-Id: References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> In-Reply-To: <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Thomas Bogendoerfer Cc: Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-mips@vger.kernel.org, iommu@lists.linux-foundation.org On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); 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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 EBEFEC43461 for ; Thu, 3 Sep 2020 08:46:53 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B8573206EB for ; Thu, 3 Sep 2020 08:46:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8573206EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8E76786C2F; Thu, 3 Sep 2020 08:46:53 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BSfFsqVaKP4P; Thu, 3 Sep 2020 08:46:50 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id EB48C86BFE; Thu, 3 Sep 2020 08:46:50 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id D6B10C07FF; Thu, 3 Sep 2020 08:46:50 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 57DA7C0051 for ; Thu, 3 Sep 2020 08:46:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 54C0D86B0B for ; Thu, 3 Sep 2020 08:46:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OH-rTxrpAUc5 for ; Thu, 3 Sep 2020 08:46:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by whitealder.osuosl.org (Postfix) with ESMTPS id 1FA1A86B0A for ; Thu, 3 Sep 2020 08:46:48 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id F0C1868CEE; Thu, 3 Sep 2020 10:46:43 +0200 (CEST) Date: Thu, 3 Sep 2020 10:46:43 +0200 From: Christoph Hellwig To: Thomas Bogendoerfer Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, iommu@lists.linux-foundation.org, Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-kernel@vger.kernel.org, Kyungmin Park X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-8.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 98B7BC433E2 for ; Thu, 3 Sep 2020 08:47:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 51F3E206EB for ; Thu, 3 Sep 2020 08:47:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="A1A4CoVZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 51F3E206EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=rg/TVDO75bdN0vxneU2L05GWNWSpwtMBrHZzsKEYokw=; b=A1A4CoVZlWTnfp+rGGbkpold7 sg426xiyTeyLurZiqPrUHLmwhl0c/M1TfuOsDBsUx7T+oZlB5//hv4y5vdWzSfhCH0NDx9XnJOk4m V0Ln4DsiVo+Vc7RwuHgsf7C2/X1m5JmdR++bhTMdFtrqIyW35SKnchL6PlE76Oa72Swycg3+QN9ZL rWb+IITZ1XYuBYX/kZtKYBXThbjczG+WjSB5G0RD3HDHQnc7VjrvlLZCJ5hJ9VbuW4rZRlC0YbFzo Rn4AqcmYID8N72GWVr+rL20WG4zZ0vdQz9+6MDW0sEecIqOw2i3yMhDwX2o4BtrdUm5KwsEGuuEPW i9PGDZezg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDktk-0008Pj-Q3; Thu, 03 Sep 2020 08:47:13 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDktL-0008DS-A0; Thu, 03 Sep 2020 08:46:58 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id F0C1868CEE; Thu, 3 Sep 2020 10:46:43 +0200 (CEST) Date: Thu, 3 Sep 2020 10:46:43 +0200 From: Christoph Hellwig To: Thomas Bogendoerfer Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200903_044647_488973_C4F5456D X-CRM114-Status: GOOD ( 17.40 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, iommu@lists.linux-foundation.org, Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-kernel@vger.kernel.org, Kyungmin Park Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Date: Thu, 3 Sep 2020 10:46:43 +0200 Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> Sender: linux-mips-owner@vger.kernel.org To: Thomas Bogendoerfer Cc: Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kern List-Id: nouveau.vger.kernel.org On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); 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=-8.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 17044C43461 for ; Thu, 3 Sep 2020 08:48:28 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CAD3D206EB for ; Thu, 3 Sep 2020 08:48:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="EOgbW3SV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAD3D206EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=J4qS7C0VgQQhJoEsCoAiFrTNNP5cGaAFXoHAW2qBWnA=; b=EOgbW3SVFru0c6SghnUf7v8Dl Yaj301/5IIl5nZDC+no1bTujRZ9KXQ2BxPYPaCbd0xWdd1vO9rpxqzA+rSM46PZmWngBPm3FOMPaO SSqXW3JU4F4o1e23cObB9a4gPw2pcrnK7jscjez+jLKPKrW3fjolNDkGNJBqZCJdiFsvBJJscSv+N qGUAZNSuqycZwtQOsYh0KJNlm6KslBB+055/tc54sa6x/UUPgiXnStDDRBStVClLkNwzSFeyvi+3Y 0vJM7om2bSdFjdmUNJrJ6lJ0b91WAtbG6HFs+r/6HYcBFu2IJRx86l9vF6vui25wqcQxw+nNCEO3s REsMfGaFQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDkta-0008L5-3N; Thu, 03 Sep 2020 08:47:02 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDktL-0008DS-A0; Thu, 03 Sep 2020 08:46:58 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id F0C1868CEE; Thu, 3 Sep 2020 10:46:43 +0200 (CEST) Date: Thu, 3 Sep 2020 10:46:43 +0200 From: Christoph Hellwig To: Thomas Bogendoerfer Subject: Re: [PATCH 22/28] sgiseeq: convert from dma_cache_sync to dma_sync_single_for_device Message-ID: <20200903084643.GA25111@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-23-hch@lst.de> <20200901152209.GA14288@alpha.franken.de> <20200901171241.GA20685@alpha.franken.de> <20200901171627.GA8255@lst.de> <20200901173810.GA25282@alpha.franken.de> <20200903084302.GB24410@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200903084302.GB24410@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200903_044647_488973_C4F5456D X-CRM114-Status: GOOD ( 17.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, linux-doc@vger.kernel.org, nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, linux-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, Christoph Hellwig , Marek Szyprowski , linux-samsung-soc@vger.kernel.org, Joonyoung Shim , linux-scsi@vger.kernel.org, iommu@lists.linux-foundation.org, Ben Skeggs , Matt Porter , linux-media@vger.kernel.org, Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-kernel@vger.kernel.org, Kyungmin Park Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Sep 03, 2020 at 10:43:02AM +0200, Christoph Hellwig wrote: > On Tue, Sep 01, 2020 at 07:38:10PM +0200, Thomas Bogendoerfer wrote: > > this is the problem: > > > > /* Always check for received packets. */ > > sgiseeq_rx(dev, sp, hregs, sregs); > > > > so the driver will look at the rx descriptor on every interrupt, so > > we cache the rx descriptor on the first interrupt and if there was > > $no rx packet, we will only see it, if cache line gets flushed for > > some other reason. > > That means a transfer back to device ownership is missing after a > (negative) check. E.g. something like this for the particular problem, although there might be other hiding elsewhere: diff --git a/drivers/net/ethernet/seeq/sgiseeq.c b/drivers/net/ethernet/seeq/sgiseeq.c index 8507ff2420143a..a1c7be8a0d1e5d 100644 --- a/drivers/net/ethernet/seeq/sgiseeq.c +++ b/drivers/net/ethernet/seeq/sgiseeq.c @@ -403,6 +403,8 @@ static inline void sgiseeq_rx(struct net_device *dev, struct sgiseeq_private *sp rd = &sp->rx_desc[sp->rx_new]; dma_sync_desc_cpu(dev, rd); } + dma_sync_desc_dev(dev, rd); + dma_sync_desc_cpu(dev, &sp->rx_desc[orig_end]); sp->rx_desc[orig_end].rdma.cntinfo &= ~(HPCDMA_EOR); dma_sync_desc_dev(dev, &sp->rx_desc[orig_end]); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel