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Date:   Fri, 27 Jul 2018 10:25:13 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Dmitry Osipenko <digetx@gmail.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Mikko Perttunen <cyndis@kapsi.fi>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Ben Skeggs <bskeggs@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Nicolas Chauvet <kwizart@gmail.com>,
        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>
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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