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Davis" , Laura Abbott , sumit.semwal@linaro.org, arve@android.com, tkjos@android.com, maco@android.com, joel@joelfernandes.org, christian@brauner.io, devel@driverdev.osuosl.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, john.stultz@linaro.org Subject: Re: [PATCH 3/4] dma-buf: add support for mapping with dma mapping attributes In-Reply-To: <20190121213028.GB28620@infradead.org> Message-ID: References: <1547836667-13695-1-git-send-email-lmark@codeaurora.org> <1547836667-13695-4-git-send-email-lmark@codeaurora.org> <20190119102527.GA17723@infradead.org> <7ae73c39-9049-bcf6-775f-b0817ba0ec5f@redhat.com> <20190121083046.GD12420@infradead.org> <0ed7875f-15e9-184f-5b99-9a53df7c8d14@ti.com> <20190121213028.GB28620@infradead.org> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Jan 2019, Christoph Hellwig wrote: > On Mon, Jan 21, 2019 at 12:20:42PM -0800, Liam Mark wrote: > > I have left this to clients, but if they own the buffer they can have the > > knowledge as to whether CPU access is needed in that use case (example for > > post-processing). > > That is an API design which the user is more likely to get wrong than > right and thus does not pass the smell test. > With the previous version of ION Android ION clients were successfully managing all their cache maintenance. 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