From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko 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 Message-ID: <1797693.ge5mZLuUEu@dimapc> References: <20180508165841.13758-1-digetx@gmail.com> <2607799.I2xByD6lqT@dimapc> <89f0794e-affa-dba0-9684-582ce5570cad@kapsi.fi> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <89f0794e-affa-dba0-9684-582ce5570cad@kapsi.fi> Sender: linux-kernel-owner@vger.kernel.org To: Mikko Perttunen Cc: Thierry Reding , Jonathan Hunter , Peter De Schrijver , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 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