Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757250AbaJIOET (ORCPT ); Thu, 9 Oct 2014 10:04:19 -0400 Received: from eusmtp01.atmel.com ([212.144.249.242]:40288 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752327AbaJIOEK (ORCPT ); Thu, 9 Oct 2014 10:04:10 -0400 Message-ID: <543695D2.1090504@atmel.com> Date: Thu, 9 Oct 2014 16:04:02 +0200 From: Nicolas Ferre Organization: atmel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Geert Uytterhoeven , Maxime Ripard CC: Russell King , Vinod Koul , Laurent Pinchart , Dan Williams , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , , "Arnd Bergmann" , =?UTF-8?B?QW50?= =?UTF-8?B?b2luZSBUw6luYXJ0?= , Thomas Petazzoni , Alexandre Belloni , Boris Brezillon , Matt Porter , "Gregory Clement" Subject: Re: [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API References: <1411746035-15882-1-git-send-email-maxime.ripard@free-electrons.com> <1411746035-15882-2-git-send-email-maxime.ripard@free-electrons.com> <7725507.nuHj4C7OxF@avalon> <5433D9AF.8020508@atmel.com> <20141007145226.GA17925@lukather> In-Reply-To: X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.161.30.18] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/10/2014 15:39, Geert Uytterhoeven : > On Tue, Oct 7, 2014 at 4:52 PM, Maxime Ripard > wrote: >>>>> +These various types will also affect how the source and destination >>>>> +addresses change over time, as DMA_SLAVE transfers will usually have >>>>> +one of the addresses that will increment, while the other will not, >>>>> +DMA_CYCLIC will have one address that will loop, while the other, will >>>> >>>> s/the other,/the other/ >>>> >>>>> +not change, etc. >>> >>> This is a little bit vague in my opinion. And usually, it is pretty >>> implementation specific. >> >> Which is why we can't really be more precise. If you have any other >> wording coming to your mind, I'm all for it :) > > Perhaps: > > Addresses pointing to RAM are typically incremented (or decremented) after > each transfer. In case of a ring buffer, they may loop (DMA_CYCLIC). > Addresses pointing to a device's register (e.g. a FIFO) are typically fixed. +1 ;-) Bye, -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/