Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753389Ab2E1FfR (ORCPT ); Mon, 28 May 2012 01:35:17 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:42191 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752549Ab2E1FfQ convert rfc822-to-8bit (ORCPT ); Mon, 28 May 2012 01:35:16 -0400 MIME-Version: 1.0 In-Reply-To: <1337941231.1580.19.camel@vkoul-udesk3> References: <1331275160-31757-1-git-send-email-tomoya.rohm@gmail.com> <1332158459-14880-1-git-send-email-tomoya.rohm@gmail.com> <20120321160913.GF3226@opensource.wolfsonmicro.com> <20120326154009.GA17506@sirena.org.uk> <20120523093857.GC4085@opensource.wolfsonmicro.com> <20120524100742.GH5361@opensource.wolfsonmicro.com> <1337941231.1580.19.camel@vkoul-udesk3> Date: Mon, 28 May 2012 14:35:15 +0900 Message-ID: Subject: Re: [alsa-devel] [PATCH v5] sound/soc/lapis: add platform driver for ML7213 From: Tomoya MORINAGA To: Vinod Koul Cc: Mark Brown , alsa-devel@alsa-project.org, lars@metafoo.de, Takashi Iwai , linux-kernel@vger.kernel.org, Liam Girdwood Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1860 Lines: 37 On Fri, May 25, 2012 at 7:20 PM, Vinod Koul wrote: >> >> > Nobody seems to be working on it as far as I can tell, I've certainly >> >> > not seen any patches. >> > >> >> If so, could you accept current platform/machine driver ? >> > >> > Ideally what would be happening here is that you or other people who >> > have such systems would be working to add the required support to the >> > core code, there's clearly a need for common code here as there are a >> > number of different systems that don't have cyclic DMA and it wouldn't >> > be great to end up with duplicated code. >> > >> > Is there some great difficulty in factoring out the support for >> > non-cyclic audio DMA on dmaengine - it seems like if there is we must >> > have a serious problem in dmaengine which we should fix? ?If there is a >> > substantial difficulty then that's different but it doesn't feel like >> > we've tried doing common code yet, if there's problems doing that I'd >> > like to understand what they are before we jump ahead of ourselves. >> >> I'm not so familiar with Linux's DMA idea. >> So we don't know whether non-cyclic dmaengine has problem or not. > First you should not be writing your own dma driver, it *needs* to use > dmaenegine. We already have bunch of driver supported, so there may be a > case that existing driver works straight or with little modifications. > Using your own dma driver is a dead road, so sooner you move over better > it is. I've never developed our own dma driver. I've developed our ASoC driver using linux standard DMA framework. -- ROHM Co., Ltd. tomoya -- 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/