From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:37292 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756042Ab2HIJjb (ORCPT ); Thu, 9 Aug 2012 05:39:31 -0400 Message-ID: <50238552.6030404@canonical.com> Date: Thu, 09 Aug 2012 11:39:30 +0200 From: Maarten Lankhorst MIME-Version: 1.0 To: Sumit Semwal CC: rob.clark@linaro.org, linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, patches@linaro.org Subject: Re: [PATCH 1/3] dma-fence: dma-buf synchronization (v7) References: <20120807175330.18745.81293.stgit@patser.local> <502162D7.9090809@canonical.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hey Sumit, Op 08-08-12 08:35, Sumit Semwal schreef: > Hi Maarten, > > On 8 August 2012 00:17, Maarten Lankhorst > wrote: >> Op 07-08-12 19:53, Maarten Lankhorst schreef: >>> A dma-fence can be attached to a buffer which is being filled or consumed >>> by hw, to allow userspace to pass the buffer without waiting to another >>> device. For example, userspace can call page_flip ioctl to display the >>> next frame of graphics after kicking the GPU but while the GPU is still >>> rendering. The display device sharing the buffer with the GPU would >>> attach a callback to get notified when the GPU's rendering-complete IRQ >>> fires, to update the scan-out address of the display, without having to >>> wake up userspace. > Thanks for this patchset; Could you please also fill up > Documentation/dma-buf-sharing.txt, to include the relevant bits? > > We've tried to make sure the Documentation corresponding is kept > up-to-date as the framework has grown, and new features are added to > it - and I think features as important as dma-fence and dmabufmgr do > warrant a healthy update. Ok I'll clean it up and add the documentation, one other question. If code that requires dmabuf needs to select CONFIG_DMA_SHARED_BUFFER, why does dma-buf.h have fallbacks for !CONFIG_DMA_SHARED_BUFFER? This seems weird, would you have any objection if I removed those? ~Maarten