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 417D3C433DF for ; Thu, 20 Aug 2020 16:54:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 274FA208C7 for ; Thu, 20 Aug 2020 16:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730380AbgHTQyV (ORCPT ); Thu, 20 Aug 2020 12:54:21 -0400 Received: from verein.lst.de ([213.95.11.211]:43094 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730001AbgHTQyO (ORCPT ); Thu, 20 Aug 2020 12:54:14 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id CF00868AFE; Thu, 20 Aug 2020 18:54:07 +0200 (CEST) Date: Thu, 20 Aug 2020 18:54:07 +0200 From: Christoph Hellwig To: Tomasz Figa Cc: 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-mips@vger.kernel.org, "James E.J. Bottomley" , linux-mm@kvack.org, 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 ," , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, netdev@vger.kernel.org, Seung-Woo Kim , Linux Kernel Mailing List , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," Subject: Re: [PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT Message-ID: <20200820165407.GD12693@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> 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-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Thu, Aug 20, 2020 at 12:05:29PM +0200, Tomasz Figa wrote: > The UAPI and V4L2/videobuf2 changes are in good shape and the only > wrong part is the use of DMA API, which was based on an earlier email > guidance anyway, and a change to the synchronization part . I find > conclusions like the above insulting for people who put many hours > into designing and implementing the related functionality, given the > complexity of the videobuf2 framework and how ill-defined the DMA API > was, and would feel better if such could be avoided in future > communication. 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. But in general it helps to add a few more people to the Cc list for such things that do stranger things. Especially if you think you did it based on the advice of those people.