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Date:   Tue, 22 Jan 2019 17:51:35 +0100
From:   Joerg Roedel <joro@8bytes.org>
To:     Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc:     Daniel Vetter <daniel@ffwll.ch>, Eric Wong <e@80x24.org>,
        David Woodhouse <dwmw2@infradead.org>,
        David Airlie <airlied@linux.ie>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        "list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>, Joerg
        Roedel <joro@8bytes.org>, " <iommu@lists.linux-foundation.org>,
        intel-gfx <intel-gfx@lists.freedesktop.org>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] iommu/intel: quirk to disable DMAR for QM57 igfx
Message-ID: <20190122165135.6rkdsxqepvmaoatn@8bytes.org>
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On Tue, Jan 22, 2019 at 04:48:26PM +0200, Joonas Lahtinen wrote:
> According to our IOMMU folks there exists some desire to be able to assign
> the iGFX device aka have intel_iommu=on instead of intel_iommu=igfx_off
> due to how the devices might be grouped in IOMMU groups. Even when you
> would not be using the iGFX device.

You can force the igfx device into a SI domain, or does that also
trigger the iommu issues on the chipset?

In any case, if iommu=on breaks these systems I want to make them work
again with opt-out, even at the cost of breaking assignability.

Regards,

	Joerg