Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753442Ab0HPM1R (ORCPT ); Mon, 16 Aug 2010 08:27:17 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:49821 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751779Ab0HPM1Q convert rfc822-to-8bit (ORCPT ); Mon, 16 Aug 2010 08:27:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=rG7tUlZjLivtrssV0vv0b0kn0jzkhyhTum5MCWVVY7vQCeh0Hbyn5fLhk0jvAh4RkR wPsjXNtvEquHUKp0I1RuzEKSLMexGF0b1ZAcbxZPp/HW7BVTDxHmhu8Gl+n+QqD0GE0O t91QpMqlsC0SzZ1PTl/vw8F8MIxocMWK8GYd0= MIME-Version: 1.0 In-Reply-To: <19561.10098.732048.877464@ipc1.ka-ro> References: <1281956870-12463-1-git-send-email-s.hauer@pengutronix.de> <1281956870-12463-2-git-send-email-s.hauer@pengutronix.de> <19561.10098.732048.877464@ipc1.ka-ro> Date: Mon, 16 Aug 2010 14:27:15 +0200 Message-ID: Subject: Re: [PATCH 1/3] dmaengine: add possibility for cyclic transfers From: Linus Walleij To: =?ISO-8859-1?Q?Lothar_Wa=DFmann?= Cc: Sascha Hauer , linux-kernel@vger.kernel.org, Dan Williams , Haavard Skinnemoen , linux-arm-kernel@lists.infradead.org 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: 682 Lines: 19 2010/8/16 Lothar Wa?mann : > Why not implement this feature using cyclic SG lists (created with > sg_chain())? This would give you endless DMA transfers without any > special DMA API extensions. That would be elegant... The driver will have to detect that the sglist is chained like an ouroboros to program the DMAC apropriately, is is easy to detect if an sglist is chained onto itself? Yours, Linus Walleij -- 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/