From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932845AbaEGQjJ (ORCPT ); Wed, 7 May 2014 12:39:09 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:59037 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756439AbaEGQjC (ORCPT ); Wed, 7 May 2014 12:39:02 -0400 Message-ID: <536A61A3.3050601@wwwdotorg.org> Date: Wed, 07 May 2014 10:38:59 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 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 Subject: Re: [PATCH v1 3/3] dma: tegra: avoid int overflow for transferred count References: <1399411343-12222-1-git-send-email-cfreeman@nvidia.com> <1399411343-12222-4-git-send-email-cfreeman@nvidia.com> In-Reply-To: <1399411343-12222-4-git-send-email-cfreeman@nvidia.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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.