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From:   Dmitry Osipenko <digetx@gmail.com>
To:     Mikko Perttunen <cyndis@kapsi.fi>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Peter De Schrijver <pdeschrijver@nvidia.com>,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v1] memory: tegra: Block DMA for clients HW on a faulty memory access
Date:   Sun, 05 Aug 2018 03:37:26 +0300
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On Sunday, 5 August 2018 03:11:57 MSK Mikko Perttunen wrote:
> One potential issue is with host1x clients where userspace processes can
> submit jobs with invalid memory accesses (addresses not mapped to
> IOMMU). If when such a failure happens, we disable the DMA for the whole
> host1x client, unrelated userspace processes may see failures even
> though there is no problem with their jobs.

Good point, I'll take a look at partial resurrection of patch [0]. Anyway I 
think it's still better to fail even the unrelated jobs, rather than to have 
corrupted memory.

[0] https://github.com/grate-driver/linux/commit/
c0351a9d01491af2b2fefc162de1c2e4fcfaa94c#diff-20226be476307cb7ec9f60e26a9c30deR378