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=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A9355C433DF for ; Fri, 21 Aug 2020 07:57:44 +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 308082063A for ; Fri, 21 Aug 2020 07:57:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="lES9dapx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 308082063A 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 B74B21698; Fri, 21 Aug 2020 09:56:52 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz B74B21698 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1597996662; bh=HsdC05tHbQtbgMyyH3TU3PqPF+I7OxbNIZUVUGQfojQ=; h=Date:From:To:Subject:References:In-Reply-To:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=lES9dapxqMy9yrK8PbaEHRnIzuu5HgaibMB7CPvx0Sjsb0g44527TZgl75OdlgAS9 k2fdB6BksqmkuGkpxZe2GmiEs3magbhIRe1PKDJqpSlU8lWV9lTYvFwump67hZ/cp0 gjlPnVRHIkMkdmOfjAealAbzb+6j7iiNclBrjsEk= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 61E65F80491; Fri, 21 Aug 2020 09:36:50 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 6A0B0F80228; Thu, 20 Aug 2020 06:52:06 +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 30DEAF80114 for ; Thu, 20 Aug 2020 06:52:03 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 30DEAF80114 Received: by verein.lst.de (Postfix, from userid 2407) id 690FB68BEB; Thu, 20 Aug 2020 06:52:01 +0200 (CEST) Date: Thu, 20 Aug 2020 06:52:01 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200820045201.GB4570@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Mailman-Approved-At: Fri, 21 Aug 2020 09:36:15 +0200 Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , 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 , Joonyoung Shim , linux-scsi@vger.kernel.org, Joerg Roedel , "list@263.net:IOMMU DRIVERS" , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , Kyungmin Park , Robin Murphy 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 Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 A7BD9C433EB for ; Thu, 20 Aug 2020 04:52:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88E1420786 for ; Thu, 20 Aug 2020 04:52:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725859AbgHTEwH (ORCPT ); Thu, 20 Aug 2020 00:52:07 -0400 Received: from verein.lst.de ([213.95.11.211]:40446 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbgHTEwH (ORCPT ); Thu, 20 Aug 2020 00:52:07 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 690FB68BEB; Thu, 20 Aug 2020 06:52:01 +0200 (CEST) Date: Thu, 20 Aug 2020 06:52:01 +0200 From: Christoph Hellwig To: Tomasz Figa Cc: Robin Murphy , Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, Linux Kernel Mailing List , "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS" , Joerg Roedel , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-mips@vger.kernel.org Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200820045201.GB4570@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Thu, 20 Aug 2020 04:52:01 +0000 Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-Id: <20200820045201.GB4570@lst.de> List-Id: References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomasz Figa Cc: Robin Murphy , Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, Linux Kernel Mailing List , "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS" , Joerg Roedel , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , linux-mips@vger.kernel.org On Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 D2087C433E5 for ; Thu, 20 Aug 2020 04:52:09 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 B2ACE20786 for ; Thu, 20 Aug 2020 04:52:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2ACE20786 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 hemlock.osuosl.org (Postfix) with ESMTP id 9E52387E60; Thu, 20 Aug 2020 04:52:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TVR-7t0-22Fn; Thu, 20 Aug 2020 04:52:09 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 2431E87E4D; Thu, 20 Aug 2020 04:52:09 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id ECA1BC0889; Thu, 20 Aug 2020 04:52:08 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 733F4C0051 for ; Thu, 20 Aug 2020 04:52:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 58A7587E60 for ; Thu, 20 Aug 2020 04:52:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fVCF2pQ5kLaP for ; Thu, 20 Aug 2020 04:52:06 +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 hemlock.osuosl.org (Postfix) with ESMTPS id 0364A87E4D for ; Thu, 20 Aug 2020 04:52:05 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 690FB68BEB; Thu, 20 Aug 2020 06:52:01 +0200 (CEST) Date: Thu, 20 Aug 2020 06:52:01 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200820045201.GB4570@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , 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 , Joonyoung Shim , linux-scsi@vger.kernel.org, "list@263.net:IOMMU DRIVERS" , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , Kyungmin Park , Robin Murphy 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 Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. _______________________________________________ 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 From: Christoph Hellwig Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Date: Thu, 20 Aug 2020 06:52:01 +0200 Message-ID: <20200820045201.GB4570@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-mips-owner@vger.kernel.org To: Tomasz Figa Cc: Robin Murphy , Christoph Hellwig , alsa-devel@alsa-project.org, linux-ia64@vger.kernel.org, Linux Doc Mailing List , nouveau@lists.freedesktop.org, linux-nvme@lists.infradead.org, Linux Kernel Mailing List , "James E.J. Bottomley" , linux-mm@kvack.org, Marek Szyprowski , linux-samsung-soc , Joonyoung Shim , linux-scsi@vger.kernel.org, Kyungmin Park , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky List-Id: nouveau.vger.kernel.org On Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. 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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 6A35DC433DF for ; Thu, 20 Aug 2020 04:53:20 +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 359FC20786 for ; Thu, 20 Aug 2020 04:53:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Yi+r+9xY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 359FC20786 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=otQJIvYGqYjCJrTdL5yzXtmgm87ijblFC7ODXp3c/bY=; b=Yi+r+9xYO948VddWtwwA1AEog 5HsG1C1NaKOl3sJmcQEbavvoJJDJbtw0wCD5dkK1/pZkjfY6VxUoLe1tlDgJTHR8XqsyvSujhBhX7 7ko/4Rr+aB9qV98QsCnCpDDTuWnnWLiLNMckUbk48paCm7ZXyj5ptT+f0tNUC282NwaVsAWrypH/Z yCLXIlE9ImC8N6WAQw0zBigsK/r4pnLACAN+rExMxHcND7r9/Gcp7wHbIud26x/82scE/oQ86EVZK TiwzntcLJl2wTQ0FOq1ahVhjYBxu+LNmNDCwaUhCGLqY6kD+JirpXfb40VCPaTuqQYFWXu8BV/mXz Ji26nDVAg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8cYa-0003Zg-Lz; Thu, 20 Aug 2020 04:52:08 +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 1k8cYX-0003YE-5L; Thu, 20 Aug 2020 04:52:05 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 690FB68BEB; Thu, 20 Aug 2020 06:52:01 +0200 (CEST) Date: Thu, 20 Aug 2020 06:52:01 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200820045201.GB4570@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <62e4f4fc-c8a5-3ee8-c576-fe7178cb4356@arm.com> <2b32f1d8-16f7-3352-40a5-420993d52fb5@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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-20200820_005205_340755_FD1B0F98 X-CRM114-Status: GOOD ( 15.98 ) 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 Mailing List , 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 , Joonyoung Shim , linux-scsi@vger.kernel.org, Joerg Roedel , "list@263.net:IOMMU DRIVERS" , Ben Skeggs , Matt Porter , Linux Media Mailing List , Tom Lendacky , Pawel Osciak , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , Kyungmin Park , Robin Murphy 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 Wed, Aug 19, 2020 at 04:22:29PM +0200, Tomasz Figa wrote: > > > FWIW, I asked back in time what the plan is for non-coherent > > > allocations and it seemed like DMA_ATTR_NON_CONSISTENT and > > > dma_sync_*() was supposed to be the right thing to go with. [2] The > > > same thread also explains why dma_alloc_pages() isn't suitable for the > > > users of dma_alloc_attrs() and DMA_ATTR_NON_CONSISTENT. > > > > AFAICS even back then Christoph was implying getting rid of > > NON_CONSISTENT and *replacing* it with something streaming-API-based - > > That's not how I read his reply from the thread I pointed to, but that > might of course be my misunderstanding. Yes. Without changes like in this series just calling dma_sync_single_* will break in various cases, e.g. because dma_alloc_attrs returns memory remapped in the vmalloc space, and the dma_sync_single_* implementation implementation can't cope with vmalloc addresses. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel