Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755327Ab1EZHgf (ORCPT ); Thu, 26 May 2011 03:36:35 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:56784 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753952Ab1EZHgd (ORCPT ); Thu, 26 May 2011 03:36:33 -0400 Date: Thu, 26 May 2011 08:36:20 +0100 From: Russell King - ARM Linux To: "Koul, Vinod" Cc: LKML , linux-arm-kernel@lists.infradead.org, Linus Walleij , Dan , Per Forlin Subject: Re: [PATCH 2/2] dmaengine: add TODO items for future work on dma drivers Message-ID: <20110526073620.GF24876@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1306323570-11133-3-git-send-email-vinod.koul@intel.com> 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: 1334 Lines: 33 On Wed, May 25, 2011 at 05:09:30PM +0530, Koul, Vinod wrote: > +1. Move remaining drivers to use new slave interface > +2. Remove old slave pointer machansim > +3. Make issue_pending to start the transaction in below drivers > + - mpc512x_dma > + - imx-dma > + - imx-sdma > + - mxs-dma.c > + - dw_dmac > + - intel_mid_dma > + - ste_dma40 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. -- 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/