From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v1 3/3] dma: tegra: avoid int overflow for transferred count Date: Wed, 07 May 2014 10:38:59 -0600 Message-ID: <536A61A3.3050601@wwwdotorg.org> References: <1399411343-12222-1-git-send-email-cfreeman@nvidia.com> <1399411343-12222-4-git-send-email-cfreeman@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1399411343-12222-4-git-send-email-cfreeman@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Christopher Freeman , ldewangan@nvidia.com, swarren@nvidia.com, vinod.koul@intel.com, dan.j.williams@intel.com Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On 05/06/2014 03:22 PM, Christopher Freeman wrote: > bytes_transferred will overflow during long audio playbacks. Since > the driver only ever consults this value modulo bytes_requested, store the > value modulo bytes_requested. The audio driver may only interpret the value modulo bytes_requested, but what about other drivers such as the high-speed UART (and SPI?) drivers? What is the dmaengine API's design requirement here, and what do other dmaengine drivers do. If it's to store the modulo, then I'm fine with this change.