Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757668Ab1EZNjJ (ORCPT ); Thu, 26 May 2011 09:39:09 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:33251 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751479Ab1EZNjG (ORCPT ); Thu, 26 May 2011 09:39:06 -0400 Date: Thu, 26 May 2011 14:38:58 +0100 From: Russell King - ARM Linux To: "Koul, Vinod" Cc: LKML , "linux-arm-kernel@lists.infradead.org" , Linus Walleij , "Williams, Dan J" , Per Forlin Subject: Re: [PATCH 2/2] dmaengine: add TODO items for future work on dma drivers Message-ID: <20110526133858.GI24876@n2100.arm.linux.org.uk> References: <1306323570-11133-1-git-send-email-vinod.koul@intel.com> <1306323570-11133-3-git-send-email-vinod.koul@intel.com> <20110526073620.GF24876@n2100.arm.linux.org.uk> <1306412730.2230.0.camel@vkoul-udesk3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1306412730.2230.0.camel@vkoul-udesk3> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1278 Lines: 26 On Thu, May 26, 2011 at 05:55:30PM +0530, Koul, Vinod wrote: > > I'd suggest adding some more to this: > > > > 4. Remove dma_slave_config's dma direction. > > > > It's pointless that dma_slave_config carries the DMA direction (to/from > > device) and the prepare function does too. It leads to DMA engine drivers > > having to verify that the two match, and DMA engine users having to issue > > two calls every time they change direction. > > > > Instead, lets specify that dma_slave_config carries the _device_ side > > parameters, which are selected according to the direction given to the > > prepare function. The memory-side parameters should be selected by the > > DMA engine driver according to its knowledge of the system. > > > > This is sensible as M2M transfers don't allow configuration and therefore > > already have to select these parameters internally. > Sure, I am adding this as well and applying both patches Thanks. In which case I'll mention that I already have patches to make the PL08x driver do this. -- 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/