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=-5.5 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 E74CCC433E6 for ; Tue, 1 Sep 2020 11:07:50 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 B4B5E20BED for ; Tue, 1 Sep 2020 11:07:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4B5E20BED 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 silver.osuosl.org (Postfix) with ESMTP id 72F302078C; Tue, 1 Sep 2020 11:07:50 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zLBc4xT2-W47; Tue, 1 Sep 2020 11:07:44 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 811E422E89; Tue, 1 Sep 2020 11:07:27 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 597BEC088B; Tue, 1 Sep 2020 11:07:27 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id B5883C0052 for ; Tue, 1 Sep 2020 11:07:26 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 8074E2078C for ; Tue, 1 Sep 2020 11:07:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id UfcemgE-2W0M for ; Tue, 1 Sep 2020 11:07:20 +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 silver.osuosl.org (Postfix) with ESMTPS id 969A527447 for ; Tue, 1 Sep 2020 11:06:24 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 508E268B05; Tue, 1 Sep 2020 13:06:18 +0200 (CEST) Date: Tue, 1 Sep 2020 13:06:17 +0200 From: Christoph Hellwig To: Tomasz Figa Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200901110617.GA13232@lst.de> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-6-hch@lst.de> <20200819135454.GA17098@lst.de> <20200820044347.GA4533@lst.de> <20200820052004.GA5305@lst.de> <20200820165407.GD12693@lst.de> 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 Kernel Mailing List , "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 , Joerg Roedel , " , 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-mips@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, Aug 20, 2020 at 07:33:48PM +0200, Tomasz Figa wrote: > > It wasn't meant to be too insulting, but I found this out when trying > > to figure out how to just disable it. But it also ends up using > > the actual dma attr flags for it's own consistency checks, so just > > not setting the flag did not turn out to work that easily. > > > > Yes, sadly the videobuf2 ended up becoming quite counterintuitive > after growing for the long years and that is reflected in the design > of this feature as well. I think we need to do something about it. So I'm about to respin the series and wonder how we should proceed. I've failed to come up with a clean patch to keep the flag and make it a no-op. Can you or your team give it a spin? Also I wonder if the flag should be renamed from NON_CONSISTENT to NON_COHERENT - the consistent thing is a weird wart from the times the old PCI DMA API that is mostly gone now. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu