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=-2.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_NEOMUTT 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 73D2AC6778F for ; Fri, 27 Jul 2018 08:25:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A8FF2088E for ; Fri, 27 Jul 2018 08:25:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=8bytes.org header.i=@8bytes.org header.b="rZABMMDy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A8FF2088E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730168AbeG0JqC (ORCPT ); Fri, 27 Jul 2018 05:46:02 -0400 Received: from 8bytes.org ([81.169.241.247]:33166 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729431AbeG0JqC (ORCPT ); Fri, 27 Jul 2018 05:46:02 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 2595525A; Fri, 27 Jul 2018 10:25:14 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=8bytes.org; s=mail-1; t=1532679914; bh=lfcxpOZdhkEgGJHUYs2LGreSEDxoS6TGO2txPpbpusY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rZABMMDyoaIA4Xe9UmPGWavmK8kK83tBJ4x21B/6C8Z0uOrBZwpYdDWXAe5/Xc5lt o4chJHeo1Bz6hhoTJJ27hNI3b20YGEAZujKBCxJ39qDtbkfhA3Q7a5zO1fXr9+ifiA gjLnWYDNp2VwxLUYlmpKYCB4LBOokOPJfNkZn93DAUPDyd++atohnfRBLAtTr4PdmM lQeUcAPKpNIO282q4ahv+RWAr9ehW5WVYssggLIJ0/74ZJy+/5ESoPD0JuAYBkUaHz P7FACIWf0hHs72lx3zkwPkBt/fttIlDPwRb7sLilOd1MElFMFWACN2SP2e9wZvsWhr RMUNKS5pAyFJw== Date: Fri, 27 Jul 2018 10:25:13 +0200 From: Joerg Roedel To: Dmitry Osipenko Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Thierry Reding , Jonathan Hunter , Mikko Perttunen , Rob Herring , Frank Rowand , Ben Skeggs , Russell King , Catalin Marinas , Will Deacon , Nicolas Chauvet , devicetree@vger.kernel.org, nouveau@lists.freedesktop.org, iommu@lists.linux-foundation.org, dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v1 0/6] Resolve unwanted DMA backing with IOMMU Message-ID: <20180727082512.lpvmeuvxnw3mpeym@8bytes.org> References: <20180726231624.21084-1-digetx@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180726231624.21084-1-digetx@gmail.com> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 27, 2018 at 02:16:18AM +0300, Dmitry Osipenko wrote: > The proposed solution adds a new option to the base device driver > structure that allows device drivers to explicitly convey to the drivers > core that the implicit IOMMU backing for devices must not happen. Why is IOMMU mapping a problem for the Tegra GPU driver? If we add something like this then it should not be the choice of the device driver, but of the user and/or the firmware. Joerg