Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755197Ab3G2HXz (ORCPT ); Mon, 29 Jul 2013 03:23:55 -0400 Received: from mga02.intel.com ([134.134.136.20]:24891 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751735Ab3G2HXx (ORCPT ); Mon, 29 Jul 2013 03:23:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,767,1367996400"; d="scan'208";a="372751775" Date: Mon, 29 Jul 2013 12:14:15 +0530 From: Vinod Koul To: Joel Fernandes Cc: Russell King - ARM Linux , Tony Lindgren , Sekhar Nori , Matt Porter , Grant Likely , Rob Herring , Mark Brown , Benoit Cousson , Balaji TK , Gururaja Hebbar , Chris Ball , Jason Kridner , Mark Jackson , Devicetree Discuss , Linux OMAP List , Linux ARM Kernel List , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux Documentation List , Linux MMC List , Linux SPI Devel List , Arnd Bergmann Subject: Re: [PATCH 1/3] dmaengine: add dma_get_slave_sg_limits() Message-ID: <20130729064415.GF29095@intel.com> References: <1374166001-31340-1-git-send-email-joelf@ti.com> <1374166001-31340-2-git-send-email-joelf@ti.com> <20130718170825.GZ21614@n2100.arm.linux.org.uk> <51E83A9D.5020008@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51E83A9D.5020008@ti.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1124 Lines: 23 On Thu, Jul 18, 2013 at 01:57:33PM -0500, Joel Fernandes wrote: > On 07/18/2013 12:08 PM, Russell King - ARM Linux wrote: > > As for the maximum number of scatterlist entries, really that's a bug in > > the DMA engine implementations if they can't accept arbitary lengths. > > I've created DMA engine drivers for implementations where you have to > > program each segment individually, ones which can have the current and > > next segments, as well as those which can walk a list. Provided you get > > informed of a transfer being completed, there really is no reason for a > > DMA engine driver to limit the number of scatterlist entries that it > > will accept. > > Sure, that makes sense. Can you point to such a typical example > implementation to get some ideas? MXS MMC driver uses this: drivers/mmc/host/mxs-mmc.c And dma engine driver for this is mxs-dma.c ~Vinod -- -- 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/